I went with Virgin and also chose a hotel with them in the centre, Hotel Parque Central, in Havana. It included transport to and from the hotel, which was very useful.
The ocean resorts are very beautiful, but pretty isolated. Public transport is almost non existent, but you can usually flag down a car and they will charge much less than the going rate of the normal taxis. They will also probably have a broken window or two, and ripped seats, but it is all part of the adventure.
I don't drink beer or spirits, and they are pretty cheap (local makes) but most wine is imported, and relatively expensive in bars. Take a corkscrew and buy bottles from the little corner stores.
When you leave, 'donate' all your medicines to the chambermaid, ie aspirin, Rennies etc. things may be changing but I don't think too quickly.
Make sure you understand the difference between the two currencies, or you will end up paying a lot more than you need to.
The hotel was very pleasant and within walking distance of the old part of Havana, which is the most interesting part of the city, but was fairly expensive.
Have a look on Trip Advisor, if you are interested, for further comments under Jennykenny.