hmmm that's a hard one. Personally, I like the idea of a docile Remus, just because I love the idea of the quiet, timid calm man, being equally docile in the bedroom. But usually when I write him this way it just doesn't work, probably because it's not really Remus whom I'm picturing as quiet and calm, but more of a fanon version.

I think regardless whether he's sub or dom, he's a strong guy. Not quite strong like Sirius, who lets you know it, but in more of a passive agressive manor.

That said I think it may also depend on the pairing. When ever he's paired with Sirius when they're in their teens I look at him as much more of a sub, while after Azkaban, I think with Sirius he would be the strong alpha. With most other pairings, regardless of whether he's on top or bottom, I think Remus is the stronger one, in a quiet, stoic sort of way.