Mexico - Need advice re beach vacation in Mexico, possibly Celestun

My wife and I would like to spend part of a Mexico winter vacation (most likely February, but could be January or March) at a beach destination in Campeche or western Yucatan. The reason for those states is that we're mainly going to visit a few (Starwood) hacienda/hotel properties in those locations, but would like to spend several days on the beach also. For what it's worth, those hacienda hotels are all within two or three hours of Merida.

We'd prefer not to go to a big tourist resort such as Cancun. We'd instead like to be near a small fishing town that has a nice beach around it. I've begun to look at Celestun, since from the little I've read so far the beach is long and nice, the town has a nice feel and at least a few good restaurants, and there is a nature reserve fairly near. I'm also curious about Chicxulub, though so far know even less about it.

Does anyone have particular impressions of Celestun? And are there any other locations in Campeche or western Yucatan you'd recommend?

Also, are there any holidays and/or school vacations we should be aware of that fall in January-March, during which the roads and vacation spots might be very crowded?

Thanks for any help

All wonderful, though rustic and nothing compared to the luxury at the Starwood haciendas. May I also add Sisal, Progresso, Rio Lagartos, Tulum, and Holbox as other places to investigate.....