Nice write-up! I just recently finished playing through MM 1 - 6 on NES (what can I say? I'm a sucker for doing things in order), and I felt like MM6 held up a lot better than I remembered. Maybe it was because I had just finished MM5 (which is pretty boring, overall), but I liked how smoothly playable it was... It was nice to breeze through a MegaMan game after some of the harder parts in the earlier games. Also, the first MM game to have branching paths? Unless a GameBoy game did it that I'm missing...
That, and the jetpack. Awesome. I really dug how the X/Wily stages were designed around your ability to use the jetpack properly, much like MegaMan 2's Wily stages forced you to use the 1, 2, 3 power-ups.