Impressive to say the least. I'll even go a step further. I've used two different Boss GT units (GT-5 and GT-6) and my main effects unit is a TC Electronics G-System. Let my say a few things about the G-Sys vs. the G7.1ut. Keep in mind I already had the G-system and also considered the Korg 3000G before picking up the Zoom. First - The G-System: The G-System lets you use your own distortion pedals in the pre-preamp loops. That could be considered a plus or a minus. It can be tricky using the four-cable method and you have to work on getting the levels right, same way it was with the Boss GT's. Basically you have to program the loop 5/insert loop to use an amps effects loop The G-System wah is one of the better ones, but nothing replaces the real deal on any effects unit I've tried. Some come closer than others. The G-System is well built and EXPENSIVE. The version 1.05 fixes many issues from the early production units. One issue was a delay in the programmable relays. The new firmware update brings that down to 50 ms instead of 300ms. TC Supports seems to be on par with a high-end manufacturer. OK - Then there is the G7.1ut. For $300 I don't think anything else can touch it. That goes for the quality of the sound and construction. I really like the footswitch design, solid feel! If I had to change anything I would've made the LCD larger/clearer. I would've paid $100 more to have a color LCD. VERY transparent sound. I've heard my share of "tonesuckers" and this isn't one of them. Yeah, you are going through A/D and D/A, but it is top notch quality. There is negligible delay in changing patches. No dropouts and smooth transitions. Versatile - Put it in front of an amp and just use the effects, it sounds great. Use the preamp and then run it into an effects return on a tube amp or use a Tech 21 Power Engine and it sounds great as well. Use the function controls to change the application. Here's a biggie - I *really* like what Zoom provided in the overdrive/distortion department. It doesn't have that buzzy/digital crap that plague 90% of the multieffects on the market. Its probably the tube energizer that makes this happen. Both units have great tuners built in. No issues at all with either and if I had to pick I'd say the G-System is easier to read on stage. Both units have quality digital effects. I have better luck programming the Zoom's expression pedal to do just about anything I want. On the G-System's side I like the "auto-on" wah that activates when you use the pedal and you can program when to stop the effect with a time parameter. If you are using the G-System and need overdrive/distortion not available by switching amp channels then you probably need a couple to put in the loops. I would say one tube screamer/Boss OD or Bluesdriver type and something like a Keeley modded Boss MT-2 for the over the top stuff. That would cover a lot of ground. Summary - If I had the Zoom G7.1ut first I honestly think I would not have purchased the G-system. When you throw everything into a G-system (expression pedal, stomps for the loops, a carrying case to protect the gear, you can easily spend $2K ! Although the G-system sounds incredible and is loaded with features, Id say the $300 for the Zoom G7.1ut and a $40 padded carry bag is a better option.