I have passed through PdC to get to the ferry that takes me out to the dive resorts on Cozumel. So I can't tell you what the hotels are like, but can tell you that the resort part of the place is fairly thin, and surrounded by typical Mexican barrio atmosphere. You get the poverty of rural Mexico surrounded by the club, dancing, drinking, beach stuff that is typical of beach resorts. If you can handle that you'll be fine. If not, then stay in the resort area and in the hotels.

One thing you might do while there is hop on the ferry and cross over to Cozumel. You can rent motorbikes and cruise up and down or around the island. The resort area is actually pretty nice. You can also take the ATF and yourself to any of the dive resorts and take scuba lessons, then hop back on the ferry and go back to your hotel. (Or just stay in one of the scuba resort hotels. They are not glamor queens like Cancun, but they are nice places to stay.)

If you think you are going to use your ATM card to get cash while you are there, then be sure to read these stories about the risks.
https://www.google.com/#q=site:+krebsonsecurity+Cancun