Gary was neutered last week and I can already see a difference. Before he was humping Becky constantly and she was getting annoyed. He would hump my slippers, violate the cat who got really angry, etc. Now I havn't seen him hump anything since the day he came home. Such a nice change! Even better, he stopped spraying Becky! I was tired of picking up my snuggle bunny and having her smell like pee. I would wipe her off and as soon as I put her down he would mark her again.
He is still leaving a bit of poo around, but that is getting better by the day. Now he's only leaving it up stairs when he sneaks out to torment my other male. His desire to sneak out is getting weaker though, now we just have to close the gate rather than locking and he stays in his room.
Gary is still very energetic and social. I would say all the positive things I liked about him are either the same or even better. He's getting more cuddly. The negatives are quickly deminishing; humping, spraying, marking territory, growling and charging at my husband (while funny, it's not a good idea since we didn't want him to bite eventually) etc.
You get to see more of their personality rather than a hormone craze. I feel like we are starting to bond now that he's not so focused on getting his freak on.