There are professionals who have worked on the Spider-Man books (Erik Larson and Terry Moore are specific names I can think of) who have said as much in interviews that Gwen was the "one" for Peter and the Peter/MJ romance should have never happened or at least never become serious. (Some comments, particularly Larson's, have IMO gone beyond personal preferences re: characters and ventured into icky nice girl/bad girl, virgin/whore territory.)
And of course the question "Did Peter love Gwen more than MJ?" has been asked since the original Clone Saga in the 70s and keeps being revived in stories like "Sins Past," "House of M," and now this.