The core effects I use a lot are a Mark Tremonti Wah (very happy with it) and everything else comes from a Carl Martin Quattro (Compressor, Overdrive/Distortion, Chorus, Delay), which I am also very happy with. I use all of these effects quite a bit and as I'm happy with them, I see no obvious need to replace or duplicate them. I know a lot of people use a looper but I don't immediately see any obvious application for it in what I play. Whatever I get, I'd like to be able to use it for both playing at home but also in a live Rock covers band with two guitarists in the line-up.
As I said, I've already tried the B9 and it was loads of fun and I can see me using it for some solos but I can also see the novelty wearing off and as the other guitarist in the band already has one, is there any point in me getting one? It was this thought that made me think of a pitch shifter as it seemed like you could get some vaguely organ sounds from it and it did other things too. However, I've never used one of these before so I'm not sure how useful they are in a live band situation. I had also toyed with a Phaser or a Flanger but I was guessing that a pitch shifter might have more applications. I might be wrong. Unless I spend a lot of money on some effect or other, I'll probably get the GE-7 as well as something else.