I have the GT2. I have to say for raw heavy distortion rhythm parts in a direct recording situation it is the best thing I've heard. I also have
a Line6 Flextone II which is basically like the old POD, and the GT2 blows it away for rhythm (metal, crunch, fast punk, palm mute, etc...)
Now I don't know how the new POD XT sounds, but I'm looking into one of those. This is because the GT2 does not have any effects or much variety. It basically tries to emmulate a Fender, Marshall, and a Mesa.
I use the Marshall setting (all 3 switches in the middle) and knobs:
Level - 11 O'clock
Treble, Bass, and Drive - All at 3 O'clock
This will give you a very near Hetfield sound. Think Master of Puppets.
The Mesa sounds too fuzy to me, and the Fender sounds thin and dead.
Here are the drawbacks to the GT2:
Not very versitile, it does one thing good (see above)
No effects (Reverb, Comp, delay, etc)
Sucks as a distortion pedal, putting this thing in front of an amp is a waste of time. It is really just a direct box.
-Takk