Help out a Mexico virgin

[scubawife]

Only a few more sleeps for me and will be basking in the sun.

But now the other question arises. For excursions, is it better to book in advance over the interwebs or will the prices and selection be better at the hotel lobby? Looking to do the Coba tour and THESE guys look pretty good (online).

Suggestions?

I've spent a lot of time in the Akumal area, but not at resorts. (We stay in a condo). We usually go where ever we want on our own, not by tours. It's easy to get around either driving, or hire a driver.

If you want a more personalized tour experience, check out iTour Mexico in Tulum and Edventure Tours, also in Tulum.