I've stayed at Villa Blanca once and Hotel Cozumel three or so times. I do prefer Hotel Cozumel for proximity to town, size of rooms, and the pool. Wifi worked fine, but I haven't stayed there in a couple years. I used Dive Paradise and have no complaints. They aren't a boutique operation by any means, but for the price, I thought the service and convenience (and options of afternoon diving!) were good.
I will add Casa Mexicana to the conversation if you are looking for good wifi. We stayed on an upper room there a year ago, and the wifi was excellent. Breakfast is included and is excellent and substantial. When I price things out, it is more expensive than the others mentioned, but not excessively so. The one downside is the pool - it's like a wading pool in an odd spot pretty much in the lobby.