jammy, I flew cubana our first trip to cuba. This was before sunwing had their own planes and they used cubana. The luggage allowance (at the time anyway) was higher than the other charters at the time, don't know about now. There was more leg room on the plane than other charters as well.
And as Gambitt said, there's nothing like starting your vacation off with a cold cristal [beer]
The only thing I don't like about them now is the flight times leaving cuba. It wasn't like that when it was chartered through sunwing. I think for a 2-week trip it wouldn't be as bad leaving Cuba early but for a week, that sucks. Not so bad for varadero because the airport is close, but for destinations like Holguin, it's not so great because you're an hour busride to the airport