Best answer: I'd never heard of them and no-one else suggested it to me.
Their website is lacking on info although they seem to have decent prices. I'm guessing that they don't have a dive shop, but work by email/phone to set up diving. No problem there as other ops do the same. I did see on their FB page that they dive out of Marina Fonatur and from TripAdvisor, people took taxis to get there - so no transportation provided (which isn't an uncommon thing in Coz.) - but none of this info is on their website.
I could probably piece some info together from different sources, but their website doesn't give much. I would guess based on what I saw that they take divers and snorkelers out together - not a plus for many divers but a definite plus for families that have both divers and non-divers.
I could add them if I had enough info on them. If anyone has personal knowledge and information, and wants to share with me, I would be happy to add them to the list.
@Mlindie4 if you use them let me know how it went.