It's a non debate; when was Professor X not convincingly portrayed as a hero and when was Magneto ever convincinglydepicted as such? I find it amazing that fanboys can wail and gnash about any kind of minor continuity inconsistency and yet they swallow hook line and sinker the alleged reformation of one of mankind's greatest mass murderers. It was always a contrived and unconvincing conceit. It would've worked fine if it had turned out to be a master scheme to lull his enemies into a false sense of security (such as in the Thomas/Adams run) but as a genuine conversion it doesn't hold any water, despite him being devolved and "resurrected without sin" in the Defenders.
Then again, they're only funny books, right....