I have this unit, purchased in November for $98. Overall, it works very well. There is the occasional lockup, where you have to remove the battery to get it working again. But it's not a big deal, and I've had that happen maybe 3 times since I bought it.
Someone asked what the memory card slot was for. I have my memory card filled with music (and use MP3s, they say they support FLAC, but it doesn't work reliably). My car has an audio in jack, so I can play it through the car's stereo. And I can control the music from voice commands. I use the verbal sequence "Music Player", "Album", "Can't buy a Thrill", "1" and it starts playing that album from track 1. A lot of times, I'll just turn on the random function, tell it to load All songs, and then just have my music randomly play.
Entering voice commands for for the navigation works just as well. The only thing that would be better is if it would verbally prompt you for the info. Instead, you have to glance at the screen to see that it's now asking for House Number, for example. But you can use the voice command to tell it the house number, and that works well.
The voice command worked through a separate wireless mic that came with the unit. It's meant to be attached to the steering wheel, but I have mine attached to a stationary handle on the driver's door. Warning, I haven't used it with the windows open, so I can't say about that. And when I'm going over bumpy roads, it can't understand me over the road noise. But on normal roads, with the windows closed, it works great.