Personally, I prefer big images on small paper... (ie: to me anything larger than 11x14 is too big.. But that's just my opinion)
I have seen specatular prints, and large ones at that, shot on 35mm by others that just sing... I just can't seem to make one that I like myself. I prefer to use 8x10 paper and keep it smaller if I can.
I do agree that certain sizes dictate something, but for me the issue is more style of shooting/type of work.
I find that I work differently in 35mm than I do when I'm shooting LF. Same goes for MF... I respond to my tools and thus the situation differently. At least for me this isn't about maintaining a certain level of grain/lack of grain in my prints...
Chipping in my 2 cents as well,