I got one a few months ago and immediately did the firmware update thingy, so it has all of those simultaneous effects ready to go. Like all Zoom products, you kinda have to dig in a bit to make sense of the features. As for me, after using the good ol' rectangular Tonelab desktop unit for so long, I found the G3 extremely confusing and hard to navigate. It's still a bit of a maze to poke through, but I'm making good use of it at the office.
What I like: delay, modulation, and reverbs are lovely. Modulated delay, hall reverb, and leslie/uni-vibe warbles are all good fun and presets sound very good, right out of the box. Pitch shift tracks very well, but is a little more "metallic" sounding than the Micro POG. Does the reverse reverb "blooming" thing nicely. Acoustic sim sounds cool, as long as you're not trying to sound like an acoustic guitar but rather messing about while stacking a
chorusy reverb'd 80s thing.
Do not like: Drive patches overall are stuffy and weird. Many of you guys have heard
our cover of T-Rex's 20th Century Boy and how the Jazzmaster roared like nothing else, which was courtesy of the Tonelab's UK/US and Dirt patches, simply having much more natural, crunchy preamp compression...None of the heavier gain settings in the G3 come close, so far. Also, so many people have been saying that the Two-Rock amp sim on the G3 is tops, but I can't seem to make it sound good unless it's blended well in a full mix, as in double tracked arrp/rhythm guitar lines. Of course, I'm pretty sure I don't have Teh Mayerz in the first place.