I went with
a Genesis 3 (similar to the GENx3) because I don't do metal and the effects & clean guitar sounds were superior to my ears. I'm more pop, country, ballads, jazz.
The Podxt has it over the rest for crunch however and if I was doing a metal, rock type thing would have opted for it's sounds. The basic amp simulations and distortion are in the "best of category" emulation with this unit. The effects however, phase, chorus, whammy, octaves etc, were nicer on the Digitech products, at least to my ears.
Most of the great guitar sounds are really slighlty grunged up but deeply layered so a Sans Amp is also a very viable option.
With all of these type units, you have to tweak the EQ to really simulate an amp. It seems the default settings never do you justice. The range of 150-300 Hz is crucial to emulating an amp sound. Most mixers will roll off this area but, out of a modeler, you need just a little to get that speaker pumping effect.
