i know this is no help but it may be imo some advice. i used digitech for years and used the gnx 2 for the last 3 years. but ever since i checked out the line 6 gear i will never go back to digitech. don't get me wrong digitech as some good sounding gear but i don't think it can hold up to line 6. if your into the computer recording check out the toneports or if not the pod floor model is awsome too. and to boot there tone libraries are huge as to the digitechs. this is all my opinion. here are two samples i did with the line 6 toneport ux1.
I use the GNX 3, which is pretty much the same, just with an onboard 8 track recorder. I have the MFX software that makes the GNX's sound great. I hated the factory presets and almost sold the unit had it not been for the new software. I'm not sure if the preset converter on the Digitech wesite works fom GNX 2 to 3. I know it will for the 4. I will send you some of the patches to try. PM me.
I too use the GNX3 and I prefer it for distortion sounds over the Line 6. I have to admit that I like heavily processed sounds though. The Line 6 may have the edge on some of the classic sounds.