Thanks, I saw that. I like the FM transmitter on the 660 so that I can listen to MP3s and hear the GPS directions through my car stereo. Seems like it would be worth the extra $100. I heard that sometimes the directions can be difficult to hear over road noise.
I'm still hopeful. I think I'd like to get the 660 for that price. The ad says minimum 6 for the 200, 4 for the c550, but the ad scan is cut off on the 600, so no way to know how many of those yet.