Of the 2 cycling tours ive been on with Exodus, i rate this lower than Sri Lanka, mainly because Cuba is just too big to cycle effectively in a 2 week period. A lot of the rides are quite long, flat, and a bit featureless. The wind can make it more difficult as well. That may be down to personal preference, but i prefer using my energy to pile up hills rather than battle on the flat for long distances. The problem with the size of the island is that pretty much every day, the ride is then finished off with a sometimes long bus transfer, which then doesnt give much advantage over a bus tour of the island anyway.
That said, cycling gives the group a common purpose, and i have found cycling or walking groups i have been with bond faster, and generally have a better group experience on a trip like this. You get a better perspective of village life by cycling through them, and can take in the wildlife and things like the sugar industry better when passing through more slowly.
The downside to the time spent cycling and transferring is that when you get to places, there are some amazing things to see, but not always time to do them justice. Im probably being a bit harsh, but with Cycling Sri Lanka being up in my top 2 of 10 Exodus trips ive been on, Cuba had some tough competition. I would still recommend you go to Cuba, but think about whether cycling is the way you want to do it.
I did have a great time though, with an amazing group of people that it was a pleasure to meet and cycle with.