First of all, the thing didn't work with the 4G phones. It caused them to spaz out and continually pop up an error message. It still did that with my 3G, but after acknowledging this once, it quit with my phone. Still, it would literally not be possible to use the mic with a 4G, so that already cuts into its usability and overall performance.
Now, the mic is pretty easy to use, assuming you are able to. Plug it into the bottom of the phone. It works with any application. Where things get interesting is in figuring out what kind of setting to use. There's a small switch on the bottom of the device that you can flick to select between the setting denoted by one wavy strip of bacon (probably airwaves, but really... it looks like bacon), two strips of bacon, stacked on top of each other, or three strips of bacon, a la IHOP style. The setting using one bacon is the equivalent of turning your volume down, so that you don't over-modulate. As you can imagine, increasing the bacon means your captured volume will be louder. However, whe you increase the bacon to get an interview to come through clearly, you also get some REALLY loud background noise. The mic picks up in 360 degrees, so you can't direct it. And if you're using a tripod, don't even bother with the thing, because it isn't going to pick up an interview any better than the internal mic.
That said, in a quiet room, this thing sounds clear as crystal. For voiceovers, I would definitely recommend this thing. It's light, it's small, it's fairly durable, you're not going to break it by storing it in a pocket while you travel. And for what it's supposed to do (assuming you aren't expecting stick mic quality) this thing delivers.
Portability - 9
Compatibility - 5
User Friendliness - 6
Clarity - 8
Appearance - 10
Overall - 7