I'll be the first to admit that I hated the idea behind One More Day/Brand New Day. But ultimately, it shows that the version of Peter Parker that is loved best, is the high flying bachelor who scrapes by in everything he does. Not the wedded college professor. Look at every cartoon and film incarnation of Spider-Man. Look at the popularity and then use that to measure which version of Spidey do people really care about.
I was only against Brand New Day because I was sick of sloppy retcons making already difficult to follow stories, even more convoluted. But after seeing the end results of BND, I picked up AMS #554-559. I haven't enjoyed reading Spider-Man this much since AMS #260 (Spidey vs. The Wizard). I agree that the way they went about retconning the marriage was pretty dumb, but I can understand their choice. Merely divorcing them, still leaves the dynamic of their interaction (Peter and Mary Jane). It also leaves Peter with much of the same disposition. Merely erradicating it all together, allows us to return to a Peter that was other wise unobtainable.
Having heroes barter with the devil is something better left for the likes of Al Simmons, but the damage is done and the end result is a much better jump off point for older fans and new fans who are only now discovering the title. As far as i'm concerned, even with the loss of JMS, BND was worth it. I won't likely buy the trade or the issues, but the result of the project has been a blast.