I think that only now can this season really begin. Sorry but Benny was a mistake - every season the writers just have to make Sam and Dean fight. And this time Benny (and Amelia) were the reason for these pointless fights. Getting rid of them both will finally let things get back on track. Yes - they both have the potential to return (especially Benny) but I hope they will no longer have the influence they did until now.
One thing that really bugged me was very awkward camerawork. Especially the scene when Crowley's face was zoomed. It looked like it had been done with a mobile phone. Also, someone manipulating Castiel is getting a bit old - but it was done in a new and interesting way - much more "direct" then before.