I myself would rather stick with Blazblue, I like the whole universe that Arcsys has created. I haven't played P4A but I don't think a story about a bunch of high school kids getting sucked into a TV is all the interesting. Also, BB is much more fleshed out at this point, reaching 20+ character now. I'm more hype for CP than I ever was for P4A.
I skipped out on Extended (bullshit release IMO) so that might have something to do with it.