I have done 6 dives in Varadero. 2 times the Russian wreck, which is the best site there. 2 times the boring Aquario, shallow, flat, boring, max 9m deep. 1 time Claraboyas 1. Bad viz, not a lot of species with fish, but ok. And Tiburones reef, also bad viz.
I would also not recommend to dive in Varadero. Have not seen any rental gear. Our boat was a fishingboat for tourists. I haven't seen any divecenter, the tanks were already on the boat and further we had to take our own equipment.
The divetime was in our case limited to 90 minutes which was ok. And the great thing was that we dove without a guide. I don't know if this is normal there. But I prefer to dive without guides. In the bay of pigs it was with a guide, but we could drain our tanks to 20 bars (also in Varadero).
They did not have enough DIN-adapters, so we got the ones from the compressor.
But diving with a divecenter in the Bay of pigs and only do 45 minute halfdives is also not my way of diving. Too short, too limited. So maybe if I had this I would be disappointed too.