Well I just ordered and recieved my garmin i3 this week, I got it from newegg for $315. I figured might as well get the color version. The unit is smaller then I thought it would be, it's really tiny. Also, it doesn't have as many features as I was hoping for. There is no trip computer that shows your average speed, etc. Also there is no way to get your longitude/lattitude displayed. This was a feature I really wanted, in case I had an accident some place remote, so I could tell a tow truck exactly where I was.
I've only used it in my car for one quick trip so far. I originally tried putting it in my front cup holder, in front of the gear shift. It sat well there, however the display was too small to be able to read the street names. I then tried putting it on my window, on the left side, low and close to the dash. I could read the display more easily, however it was harder to reach the buttons. Also the suction cup failed and it fell down while I was on the highway, not cool.
Once I find a good place to stick this thing I think it will work out well. I might end up trading it for a better model in the future, if I find that I use it a lot.