I'd say that anyone interested in visiting Tulum, Chichen Itza, etc., as the OP might be, shouldn't get one of these. They're fine for someone who wants to hang out on the same beach for the duration and avoid any hassles. (I'm not making value judgments about one type of vacation versus the other, just saying that they're different, and an all-inclusive deal is better suited to one of them.)

If the OP wants to get a bit further away from the totally-tourist experience, s/he might consider moving down the coast a bit to Playa del Carmen. Still lots of tourist amenities, all the facilities, etc., etc., but not quite as single-minded about it as Cancun is.