Below is an accumulation of information I found when I was researching the G2Nu guitar mutli-effects pedal.
Bookmark this page. It has ton's of useful links to information for this pedal as well as similar pedals.
I needed a small, battery powered, pedal that I could use when I was away from wall sockets. I also wanted to get a feel for as many other effects pedals as I could. This pedal fits the bill perfectly. Below is a comprehensive list of features.
Here is a list of the amps, stomp boxes, and original sounds that the Zoom pedal produces. These are the main drive effects that you base your sound on. Short descriptions of each of these are available on Zooms website.
This list of effects and a little more detail about each of them is provided in the official G2Nu / G2.1Nu Manual.
As with anything, this pedal has a couple of cons among it's huge list of pros.
First, the looper only allows for 5 second loops. That's enough to dip your toes in the water, but a looper might be your next purchase, if you're into that kinda thing.
Second, you can only have one effect per module at a time. So, you can't combine a Vox OC-30 with a BOSS OD-1 (they are both drive effects). You probably won't want to and I'm really just rehashing a comment I saw repeated a few times.
If you decide to buy, please buy your Zoom G2Nu on Amazon using any link on this page. I'll get a tiny commission when you do and it doesn't change the cost for you at all. My G2Nu cost less than $90.
After researching the heck out of this Zoom, I decided to buy the Boss ME-25. The Zoom seems better in every way except one. The looper on the Zoom is only 5 seconds while the ME-25's is 35 seconds, and I think I want to loop. I could buy the Zoom and a Ditto for about the same price, but I just decided to give the ME-25 a go. Here are links to the ME-25 and other similar pedals.
Trademarks are those of their respective companies. All of the effects are simulated.