The deal-killer for me is the lack of VST support. Without Nebula and the free amp sims out there it's as useful as tits on a bull for tracking/mixing for me.
Still getting it to be rid of this damn Mbox though. I edit drums and vocals in PT, its workflow with voc-align and batch processing makes it more useful/quicker for me than Cubase. Mixing, guitar tracking, guitar editing etc. still done in Cubase. Bass editing could be done in either more or less. Elastic Audio X-form is pretty good with bass, but so is slip editing.