We went (childlessly) in 2002 and had a fab time. We went independently though, not to Varadero, so I can't tell you anything about that.
We stayed in Havana, Santiago de Cuba, Camaguey and Trinidad and enjoyed Havana and Trinidad most - Camaguey was pretty quiet at night bar-wise and Santiago was more tourist-filled than the rest when we were there (cue lots of attempted rippings-off by hustlers).
Things may be very different now - when we went you could buy a lot of things with US dollars, far more than with pesos, so locals were always trying to hustle dollars out of us - often very charmingly, but it got to the point where we were deliberatly avoiding talking to Cubans because so many ended up asking us for dollars .
The food can be ropey, but it was the lack of range that did our heads in. The only street-food was cheese pizzas and orange squash, and private restaurants were only allowed to serve chicken, fish or pork (although some serve lobster, illegally). Beef was only available in state restaurants, but it was often sold out when we tried to order it.
Fortunately, Cuban beer (esp Cristal) and cocktails more than make up for the food, and the live music is very good.
I'd deffo recommend wandering round old Havana, and a trip to Trinidad, which is full of Spanish colonial buildings and has a nice mellow kind of atmosphere.