It sounds like things went very smoothly!
I've had 7 gliders neutered, and in every case, they have been back with their cage mates the same night. If they don't have complications, such as Self Mutilation, they hardly know anything at all happened! Just keep an eye on him. As for the pain meds - the vet will tell you how often to give them. Just follow the schedule, don't wait for him to show pain.