Jeez - he's 3 and already dry during the day?
Most of the parents I know didn't make any progress on toilet training for boys until the year before they went to school
I guess if he's ok in daytime you are doing the right thing by getting him up when you go to bed. If he's not wetting the pull ups too often I don't see what the problem is.
When mine started being dry overnight we swapped to those absorbent sheet things (well 2 of them actually since they then covered about 3/4 of the bed), so if there were any accidents he just got up, changed his shorts and stripped off the top sheet (have 2 undersheets with the pads between) and put it in the washing basket, and left me to dispose of the absorbent sheet. My kid used to get really upset when he'd wet the bed, but this system seemed to work since he felt he was able to make ammends by stipping the bed and I didn't get wound up 'cos it just involved washing a sheet and a pair of bedtime shorts, and chucking something in the bin - rather than spending 15 minutes in the morning spraying Fabreze over the mattress and shouting at my kid