"We are looking or something that isn't super busying knowing that we are going during the busiest week."
Mmmmm, good luck with that. Christmas is going to be pretty crazy no matter where you stay.
First of all, since you want a "nice pool", you'll definitely want a place that HEATS its pools - which isn't as common as you'd think.
Secondly, do you want AI or non? If you plan on doing lots of excursions, it can be a lot more cost effective to go non-AI but you may have to forego some of the amenities (like multiple pools and kids clubs) that you'll find at AI resorts. If you do want non-AI, then you'll definitely want to be in town so you have easy access to restaurants etc. El Taj is a very nice, higher end condo development right in Playa del Carmen that gets rave reviews but I don't know if their pool is heated.
If you want AI, then there's the Barcelo Maya is a complex of five resorts in one. The higher up the chain you stay, the more access you have. Lots of pools and great snorkelling right off the beach. It's located in Puerto Aventuras, so not too far from lots of excursion-type places - e.g. Xplore, Tulum, Akumal. Again, I'm not sure that their pool is heated.
Both these recommendations are shots in the dark though. It would be better if you could provide us with more information as to what you're looking for - i.e. AI or non, kid friendly or adult only (I appreciate you're a family of 4 but how old are your kids?), is a good beach important to you and, the most vital subject of all, what's your budget?