I have a Woot (1/6/2013) Ikey Audio G3 Portable USB Instrument Recorder. It works, and sounds fine to me. I'd like to point out some negatives though.
Use good batteries. With a current draw around a half amp, the iGo rechargeable Alkalines just won't do it.
If there's a way to delete recordings, I've not found it, except by using a computer.
For mine, it will no longer connect via USB to the computer and I have to resort to moving the SD card to a computer. Don't know if that's a design flaw or my unit is failed, probably failed.
The VU meter seems to be linear and low resolution, that's ok but doesn't really give a good feel (signal comes on a little too suddenly as you raise the level).
I've been using it in parallel with a netbook running audacity, audacity is winning the race for most reliable, it's just a bit easier to mess up with the little G3 device, which is not a good thing when recording live (never again to be replayed) material. Even when it's not the device's fault (bad cable), it's just harder to figure out what the problem is when all you've got is a VU meter.
fyi: I use stereo CD quality WAV recordings, occasionally mono, haven't tested mp3 recording.