It is definitely worth it, to see if you are going to like it enough to get certified if you are undecided. We did a Discover Dive with three dives in Playa in 2005 at Scuba Libre (not even sure they are still there?). In fact, we had planned to get certified in Cuba this year and couldn't, but still did another five 40 foot (ish
) dives at a great shop there.
One year we will get around to getting certified.
I have been really happy with diving at that depth though, nice and lights and lots to see, and it's true you can stay down longer the shallower you are.
We just booked when we got there but it might be a good idea to book ahead. I have also heard very good reviews of Geofish.