Wow, Revolucion de Cuba is a great venue. It's been expensively decked out as a marketing man's idea of a pre-revolutionary Havana bar. It has a nice atmosphere, good lighting, a great wooden floor and a good sound system.
The classes are pretty busy and the dancing after the classes is good. Numbers for the free dancing could be better, but there are always some really nice dancers there. I had a lovely dance last night with a recent arrival to Cardiff who's amazingly expressive and fun to dance with.
The music mixes LA/NY and Cuban style, plus some bachata and a bit of lambada/zouk (but not too much). If you're a Cuban-style dancer, that's no problem - go to Sabina's class in La Tasca first and then come on afterwards, Revolucion is open until at least midnight. There is occasionally some rueda.
Quick final point: after 10pm it's free to get in for the dancing, but please buy a drink or two at the bar - it helps to secure the future of the venue.