We stayed on Yacht Leigh at the end on February celebrating one of our friend's 50th birthday.
The owner sorted taxis from the airport (€35) to meet us and drop us off / pick us up right at / from the boat gangplank.
There were 4 couples, so we each had our own private bedroom with en-suite. We drew lots for who had the 2 doubles and who had the twins (we got a double !!) but everyone said their beds were very comfortable and showers were surprisingly good. The weirdly high toilets were a bit strange, but we all managed !!
Each room had a central heating control so you could keep your own room as you like it (although we were there in Feb, it was never cold anywhere inside the boat).
Everything was exactly as you see in the photos. There was a strong wifi and even an Aux cable connected to an amp and speakers which meant you could play your own or any internet based music (e.g. Spotify).
There are loads of restaurants within the marina, we ate at the green one (can't remember it's name but you'd spot it). The tapas looked a bit pricey at about €15 a plate but the servings were HUGE so great value. There were cafes, a small Burger King (if your kids won't eat anything else) and a shop for buying anything else you might need (breakfast, wine, beer, beach towels, sunhats, etc, etc)
Outside the marina there are taxis, buses (inc the tourist open-top type), casino, more restaurants, etc, so the boat is a great place to stay as a base to explore Barcelona. The large sandy beaches are less than a 10 mins stroll away from the boat.
Be warned 'though, we enjoyed our time on the boat just relaxing together, chatting, drinking & dancing that we 'stayed-in' on 2 of our 3 nights so didn't see a great deal of the Barcelona nightlife !!
On the last night, as a surprise, the Birthday 'Boy' had arranged with the owner to have a chef come on board and cook a delicious authentic Spanish meal for the 8 of us. I don't know what it cost, but it was a lovely experience.
I'm not a fan of boats (still not a fan in open water), but as it was always moored between lots of others, there was very little movement at all. In bed or upstairs with the window blinds closed, you could hardly notice you were on a boat (if at all) and even when on deck the movement was more a horizontal in-out left-right than rolling. Definitely no need to worry about sea-sickness (unless you pay extra for a captain and take the boat out to sea ...)
Security was Ok. There was a safe in one bedroom which we didn't use, but we hid our valuables around the boat and followed the instructions on locking up / not leaving valuables in site / raising the gangplank at night and it felt a safe environment. We were actually questioned twice going back to the boat on our first evening and 2nd day by a marina security patrol, so they are clearly aware of new faces). There are also so many other large, expensive and unattended yachts in the marina that security has to be good or people wouldn't moor there.
All in all, our stay in Yacht Leigh was superb, and good value when you consider each couple paid less than £200 a night to experience a little of a millionaire's lifestyle in one of Europe's prettiest major cities (apparently ... we may get to see more of it next time we visit, as we will be back!!)