From the view of a teenage LEGO fan, I can say that the Duel on Mustafar set gets the job done. I bought it for 2 reasons:

A. Episode III is my all-time favorite Star Wars movie, and I love the Mustafar duel.

B. I needed a new Episode III Obi-Wan.

This considered, I think it did a fair job. The minifigures are excellent, and I will not judge them on their use in later 2020 sets.

The Obi-Wan is stellar, and the burnt detail is noticeable, but not too much so it is not able to be used as a normal Episode III Obi-Wan. The face really captures how the character feels during the duel, yet I feel that the stern face is a bit odd looking.

The Anakin is awesome, and, once again, the burn marks are subtle enough for use outside Mustafar. The "normal" face represents Anakin's bitterness in the film, and the yellow eyed Sith face is down right creepy- in a good way.

Overall, the minifigure selection is exactly what belongs in a Mustafar set. However, the build is another story. It represents the scene nicely, and has great play features, like a lava sprayer and the ability to customize your duel in 2 ways. However, many design elements are kind of bad. The flames on the set fall off ALL THE TIME. The blue technic pin holding that one column is an eyesore, and the abundance of red bricks is really weird. Lava is not straight red, it is translucent orangish. While LEGO might not be able to make those pieces trans-orange, it still looks bad. However, the largest issue of all is that there is no high ground. There is no rock area for that famous scene, which is really stupid on LEGO's part. Also, on the battle platforms, Obi-Wan's is LOWER than Anakin's, meaning that he has the low ground. This is really inexcusable, and really hurts the set.

Overall, this set does what it's supposed to. It has great minifigs, and provides a nice duel for anyone who plays with their sets. It's just the weird piece decisions and absence of some parts that knock it down. It's a great $20 set, but it could be better.

Summary: Don't get me wrong, the 75269-1: Duel of Mustafar set is not a bad set. Not at all. The minifigures are excellent, by far the brightest spot of the set. However, it is not a great set. It does justice to it's older counterparts, and finally recreates the classic scene. (In my opinion, LEGO took too long to make another model of this — in fact, I was just thinking they should create another when I found out this was coming out.) The downside to this set is its simplicity and uncomfortable nature. I find it difficult to use anywhere, and it is not the most complex or beautiful model. Unless you are acting out the final scene, the model has little use. For the majority of the time I've had it, it has been sitting around.

Build: I do think the build of this set is great. It is a small set, designed for children. The platforms resemble the platforms from the scene in Revenge of the Sith (2005). Their detail is nice, especially the blade pieces on the circular platform and the little control panel on the other. It is simple but just right. The bright colors stick out, but it is a lava planet. The transparent orange 1x2x5 piece, or however many studs tall that is, is a very nice touch. I don't see too many out of place pieces (probably because there are no technic mechanisms). The tall falling thing with the helicopter blades is a nice action feature, and I like its place in the set, although I'm not exactly sure what it is... overall the build is nice, simple, and playable.

Playability: This brings us to our playability. This set is intended to be playable and simple for children. A similar set would be the 75229: Death Star Escape set. This is not exactly a collector's item or a showpiece unless you want it to be. The platforms spin and move along their tracks, allowing the minifigures' lightsabers to clash if turned. It's a nice feature and the main one of this set. There is not much other space to place minifigures or act out other parts of the scene.

Minifigures: Honestly, the minifigures are the reason I bought this set. They are beautiful. The robes look similar to past renditions, although probably a bit more detailed. The torso and leg prints are movie-accurate and I love the picks in the robes (presumably from sparks/flying lava or lightsaber brushes, although the Obi-Wan Kenobi minifigure in 75286: General Grievous' Starfighter has the same picks, and Grievous dies before the Mustafar duel so maybe Kenobi got the marks from Grievous too?) Obi-Wan and Anakin have similar, if not the same hairpieces as their earlier counterparts. Anakin's faces are excellent; the one is a serious face that radiates with his conflicting emotions, and the other depicts his anger. My only complaint would be about Obi-Wan's faces. One face looks anguished, and the other is fierce and unlike him. I would have liked to see an alternate fierce face that actually looks like Ewan McGregor and would be more usable in other situations.

Cost: With 208 pieces, the price-to-part ratio is right on the money, literally. (A general rule is 10 cents a piece) For $19.99, I would have liked to see a little more on this set. There are few large pieces, so I could see some more pieces on this build without raising the price. Or, I would like to see this on sale for maybe $15. You could probably find it on sale somewhere; I would recommend looking for a sale.

Recap: This upgrade to the Duel on Mustafar from 2005 is not without flaws, and it's minifigures are its brightest spot, but it is still a quality set, especially for children. I do not regret my purchase at all.

Duel on Mustafar is a great scene in the Star Wars universe.
It being depicted in a Lego set is a good thing but this set is disappointing.
First, i think the price is too high, the set is small and comes with 2 minifigures.
Working with this size is a bad idea because you have to forget many interesting parts or make them very small.
The platforms are very disapointing especially compared to those of Lego 9494.
The choice of colors also. The yellow does not work well and the red could have been replaced by transluscent red and transluscent orange.
I am also disapointed by the minifigures. Obi-Wan Kenobi beard looks weird, i prefer the old beard that looked nicer.The frightened face does not look right, Obi-Wan does not seem to be frightened during the duel, a disgusted face would have been better.I do not get the worn clothes also, yes there can be projections of lava that can worn the clothes but it does not looks that good and makes him hardly usable for other scenes.
On Anakin Skywalker, it is more discret. He looks very good if we except his head.
The neutral expression is good even if it hardly looks like Anakin Skywalker. Once again, the Anakin Skywalker in Lego 9494 is way better. I do not like his sith face, the mouth expression is too pronounced. I would have prefered a normal face for him, maybe even smiling or less indifferent or a sith face than the one he has and one half burned.

But the set has great features. The sliding platforms are great for playing. It works well. Only Anakin is not well on the jumper, he can easily fall but maybe this is intended.
The lava projector is nice but when moving the set, lava studs can fall. I placed them on the build in order to avoid that.

I would have prefered a bigger and more detailled set , with more minifigures but this set is not that bad.
It is also a good occasion to get Obi Wan Kenobi and Anakin Skywalker but i prefer the build in sets, this is why i am disapointed.

SOME HISTORY

Do you want a little diorama that represents one of the most iconic lightsaber battles of the prequels trilogy? The first attempt made by Lego came in 2005 and it was a big weird playset which looked like a videogame arena. Despite having light-up lightsabers it was pretty messy and didn't really work very well. The second attempt was within Anakin's jedi interceptor, the green one, in 2012. Basically it was a starfighter beefed up with more figures and two droid platforms on the lava, just to hint about the duel.

THE MINIFIGURES

Anakin looks splendid. It comes with two expressions, one of which has yellow sith eyes. I'm not a big fan of his hairpiece though, I would have preferred a new mould since it's the same from TCW, but here he's supposed to have longer hair. Details of burning clothing are great on the torso, back and on the legs.

Obi-wan is very well done and again, he's very detailed. Probably this is the best version of him.

THE SET

The scene is split in two bags and it took me 15 minutes to build it.

The main build is a single structure which could be opened up to form a long line or closed to be more square-like. The colour scheme is made up of a lot of tiny bricks with different shades of red, yellow and black representing lava and volcanic rock. There are two droid platforms which could wheel 360° or slide back and forth along their track. There is a little box that might be pushed to release three studs in the air. That doesn't work very well, since a lot of times you'll end up pushing it by accident and the studs are very easy to loose, but it might add something to the scene. Finally, there is a column that could be raised up or kept down like a bridge, and you could duel on top of it as well. I like being able to keep it high like a tower, but the technic connections are very basic so it tends to fall all the time.

CONCLUSIONS

Personally, I just love this scene in the movie. So I'm very happy to display it on a shelf. It doesn't take up a lot of space. Also, it has huge play value since you could fight with them everywhere on this little playset. Of course, it's nothing spectacular, and it has a few little limited parts, but for the price I think it's a good little set.

BUT since there's no true high ground I cannot be 100% satisfied. Still, a major improvement compared to his predecessors.