Just back from Cancun and decided to check out the Aloft for a couple of days at the beginning of our vacation. For us:

The positives:

Good location: Top of the "7", right in the middle of the action...
Good redemption: when rates are otherwise high
Staff: No issues, but they seemed stressed at times to get things done

The negatives:

No beach (as noted by others)
Mold & Mildew: like other CUN properties, but the smell was everywhere (hit us the moment we walked in) and even a crack in the wall near the window in our room leaked water when there was heavy rain.
Operations: The 2 days we were there the lobby was filled with people waiting for their rooms long after the 3 pm check-in time. (We waited until nearly 4:30 ourselves). We saw housekeeping preparing rooms until late in the evening.
Rooms: Small and little or no storage. Leave clothes in your suitcase is probably the best plan. Not a fan of the sliding glass door that is also the door to the one small closet.
No beach:

For us it was worth the points to research this, we were hoping to find a go-to 1 to 2 night stopover hotel (can't stand the mold at the Courtyard CUN either, so that's out), but in the future we'll probably just priceline a night at the Westin versus staying here again.