I thought I had responded to your question yesterday, but it seems that cyberspace has swallowed the response--but if two show up, pardon my verbosity....
We usually stay at the Fiesta and like it alot. Actually we prefer its out of downtown location! The food at the Fiesta is okay, but we usually just eat breakfast there and go into town for dinner. The taxi ride is $5.00 one way in our experience, but maybe that is because I speak Spanish..I don't know. We were there last in November and I cannot imagine that rates have gone up so fast, but... The cost of meals downtown is very reasonable, so I do not consider the "extra" cost of the taxi prohibative. We really like a restaurant called the French Quarter, and think it is the best in Coz, but not everyone on this Board agrees with that assessment.
We do not miss the night life in town. Maybe that is because we are in our 50's--but not yet ready for the geriatric ward--we go on dive trips 4 times a year and typically log 75+ dives a year.
It is true that Fiesta really does not have much of a beach, but the pool is great! And their are lots of chaises for the sun lovers--many down near the shore where there is access to the ocean.
Also, the shore dives at the Fiesta are great! We usually make our first dive in Coz a shore dive at the Fiesta--max depth of ca. 25 feet--and have seen lots of sea life including eels, crabs, French Angels, Queen Angels, Gray Angels, Yellowtail Snappers and all the other "usual suspects".
We have dived with the Dive House and find them to be quite good. If you stay at the Fiesta and dive with the Dive House, you can get a locker for your gear near the dock--a great convenience. A company called Island Dreams can arrange a very cost effective package for the Fiesta/Dive House.
We usually dive from a boat that caters to more advanced divers, but we did some dives with the Dive House last November and found them to be, as I noted, quite good. They seemed to do very well with less experienced divers...
But, my guess is that whomever you go with and where ever you stay, you will enjoy Coz: it is a wonderful place to dive! Enjoy, enjoy, enjoy...
Joewr