Does your son have any speech problems? Does he have a nasal sound to his speech? If he sounds nasal AT ALL, tell the ENT that you do not want an adenoidectomy without a nasal endoscopy being performed to make sure that removing the roof of his palate won't cause problems. He CAN "shave" the adenoids so that they are smaller and less troublesome. You do NOT want hypernasality or hyponasality issues coming out of surgery, I promise you. Part of what the nasal endoscopy will do is check his structure to make sure that there isn't an issue with it.
Removing large tonsils and putting in ear tubes can really help give your child relief. But please tread carefully with the adenoids. They cannot be seen without a nasal endoscopy.
As far as recovery time is concerned, give it at least a week. Maybe more. Keep medicine in him - don't miss a dose. The pain is considerable the first 3 days and you want pain meds to stay in his system throughout. I would actually have ear plugs made for him, even though some people say they don't need them. I would NOT let him in a pool without ear plugs, really and truly.
Good luck!