I've got the g9.2tt.
DI tones are actually reallllly nice.
As long as you realize that you will not be able to use tones you program to use with your amp DI.
As long as you mess with the tones you can get it sounding real. You have to experiment with anything of course. I don't DI anymore with it because I like micing cabs

but thats not because the zoom is bad.
Now with the clean tones I didnt use the cab sim, but with the OD tones I did.
I didn't record into a PC soundcard, but I did run it through a Tascam recorder, a behringer mixer, a peavey system, and two other p.a. systems for live playing and experimenting and the sound was just as I had originally set it up on my mixer. Which was a big plus for me because it meant it was a pretty true representation instead a constantly shifting sound from system to system.
As a matter of fact I was so impressed with the guitar one, that I even bought the zoom bass processor and DI with that. I split the signal into a tradition amp/mic setup and the Zoom DI setup.
Zoom makes some amazing stuff IMO.