I'm a huge fan of progression. Dick Grayson becoming Batman. Bucky becoming Cap. Those things really worked for me. And while Otto becoming Peter is a bit odd, the same principle applies. It was / is a real opportunity to do something new and fresh w/ "Peter Parker." I mean...we;'re looking at the same character we've generally enjoyed for years...with someone else's voice in his head. Someone who's changing. Growing. becoming something superior to not just what they were - but to what Peter was, as well. Or at least trying to.
I like Slott's story telling...but reintroducing Peter SO soon really came across as invalidating of the final pages of #700, and a big, missed opportunity in regards to some progressive story telling for Otto and eventually for Peter.