I have been using the GNX4 for over a year now. It truly is an awesome piece of equiptment. It is what brought me back to the guitar scene after a 19 year hiatus. It is exactly what Digitech describes it as, "A guitar workstation". It is my midi/computer sound card interface for recording to DAW. It also is a my portable 8 track recorder that I use to quickly capture riffs that I may use for original songs. The onboard MP3 player is very cool for playing backtracks thru my studio monitors while playing along through my guitar amp. The onboard drum machine is great when jamming in the bedroom with a couple beers. The amp modelling and effects capabilities I am told surpass Podxt but I have never tried a Pod so I can't confirm that. I do know that the tones this thing generates are quite spectacular. The stock patches that come with the GNX4 are pretty good but there is a sound engineer who has created and markets his own patches that are something else. Right now, I use it for gigging but I am looking into a Carvin Legacy as my main gigging amp because well.......nothing beats a real tube amp but if you looking for an amp modeller, nothing comes closer then a GNX4. IMHO!
I'm sure I'm gonna get blasted by Line 6 users very soon.