Tricky one we have both here 3 greens and 2 boscs and all have their little quirks. Its alot of luck as well if im honest boscs and greens alike all have different temperments our 3 greens go on a scale i have one female shes a complete softie and will let you do anything to her, our male gibbers is the inbetweeny hes a sweetheart but has his moments and will shoo the others off their basking spots if he wants it himself, now our last is katie shes also our oldest and newest, she doesnt like to be touched, was worse when we first got her it took alot of time and patience but now all she does is head bob and shake when we try to move her or pick her up.
The boscs again from one end to the other i have a female thats a little lamb she again will let me do anything with her but i do have to watch my toes when i go into their room as i could end up with a bosc attached to one, the male is a typical bosc he hisses puffs and occasionally will attempt to bite me although Fixx has no trouble with him.
I know people with iguanas that are lovely and will actually approach them and sit on their knee but i also know people that have iguanas that bite whip and are just nasty (a few were because of a previous home iguanas are very inteligent and never forget) I also know people with boscs that go from one scale to another.
I recommend what someone else has already said go and visit a few people with one or the other or both and see what you think when you see them in their homes with their owners
Im not trying to put you off honest i have just realised how negative my post look sorry
(our boscs freeroam the viv room and our iguanas free roam the front room)