I appreciate all the reviews on this site and agree that for a family trip with kids, this is a great choice if you must choose Cozumel. We have stayed in many places in Playa Del Carmen and a few in Cozumel. Obviously , you cannot compare PDC accommodations with Coz. The staff great, the shows for kids. Some have little kitchenettes, some nothing, some small bathrooms, some bigger bathrooms.
Furniture is different in each room, and some rooms are awful, some nicer.
We stayed in two different rooms while we were there. One was pretty good the other yucky. The thatched roof leaked and boy, you could really hear your neighbors. I would say, if anything could be changed at the Allegro, it's the rooms. We were disappointed with the rooms and maid service.