I think it depends on the point of the MVPs - is it to give out an award, or to stimulate discussion on the games etc. In my view, the point of them atm should be the latter, in which case I'd prefer more detailed writeups on fewer games, rather than more games but no detail.
I should add, that dependant on the format we go with MVPs, I'm willing to help out, though I would rather do the writeups for a league I'm not in (I enjoy reading what other people write about my own players, which I lose if I do the writeups for my own league!)