I'll be the dissenting voice here.
Of
course the screenshots of the old game look 'cleaner' - the visuals in the original game were less-detailed to begin with, so they retain a clean look when scaled down to miniature size. The PSP remake suffers by comparison in these shots because the added detail becomes difficult to pick out when scaled down, and ends up making the images look a little muddy and blurred by comparison. Larger screens of the PSP remake will probably show it off to better advantage.
I also think the MMX8 polygon look is more appealing than the oldschool MMX sprites to begin with, which doesn't hurt matters either. If you want 'charm' and can't stand the revamped look, there's always the Megaman X Collection, or Rockman Rockman (if you find 'Megahead' charming).