I really enjoyed Mega Man Legends and its sequel, but... yeah, the controls are pretty bad. The enemy AI is even worse though, and you can usually just lock on and circle strafe everything to death that isn't a boss. Most bosses go down from that too.
I'm not sure what exactly it was about the series that I liked so much though. Could just be nostalgia.
And while Mega Man 7 is really not much of an upgrade over 6 from a game mechanics point of view, I'd argue that Mega Man as a whole honestly got pretty stale by Mega Man 3 or 4 anyway. Mega Man X is a different beast though, and I'd say its gameplay and story are sufficiently different to be worth playing. I really enjoy the change in gameplay with X, where his increase in mobility from dashing really changes the way you fight bosses and get around levels. And this may be bias or nostalgia talking, but I really feel like the levels in the X games are better designed with way less cheap BS to kill you like the original series. The story is a little more serious too. Like the original series though, it gets pretty stale after a few sequels.
On the subject though, I just got around to playing Mega Man 9 and the rage has returned. I don't know why, but it feels like the level designers thought that every level needed a massive difficulty spike about halfway through. All of the levels are pretty short, but have a platforming section that kills you enough to pad out the gameplay. Plug Man's disappearing block puzzle in particular gave me PTSD.