Played the PSP remake and it was fantastic! I always loved the Mega Man platformers. They're difficult, but possible and rewarding. Trying out the new weapons is exciting, and the music is fantastic. I seem to have a bad habit of just getting all the weapons, and then never bothering to finish the final levels. Not because they're hard, but because the game becomes a bit more repetitive at that point, and you have all the weapons, so there's not much more to look forward to. I did finish Mega Man 2, though.
As for the iOS remake, well, the controls are already a flaw, but why is the frame-rate and presentation so awful? I mean, the text is hilariously generic, the text boxes are just black squares, and the fact that it has to load each individual part of the level is pathetic. Also, downloadable content for a SNES game? Really?
I don't want to hate on it too much, since it's still Mega Man X, but that's pretty lazy.