Just hooked mine up tonight. The sound quality is excellent as everyone has mentioned. I had an FM transmitter before, and there really is no comparison. The only sound issue I have is that my songs are all different volumes, but I just need to spend some time in iTunes to fix that.
I had a few unique issues come up during installation that I hadn't seen posted before:
1) I had almost no room to pull out the unit because the hazard light plug was so tight, but once I got the hazard plug out I undid some of the tape holding the wires together and gave myself some room to maneuver.
2) The grounding wire for the radio (at least I think that's what it was - square black plug with one wire next to "7.5 ohm FM" on the heatsink) was the trickiest part. It took me a while to find the release, and it didn't help that this was one of the shortest wires.
3) No problem getting the sub grounding wire off the radio harness. That was easy.
4) The board came shipped with the 2" ribbon cable plugged in the wrong way. I was able to figure it out and plug it in right the first time by looking at the pictures on the install CD, but it caused a lot of confusion when I noticed that it seemed to be plugged in backwards at first. Jazzy, you might want to make a note of this in the install directions.
5) I used the inCase Dual Input Charger which has worked well so far. It's kinda big, but it has the line out, clean cable to the iPod (unlike the Monster), no cheesy line amp (unlike the Belkin), and you can also take it out of your car and plug it into the wall (unlike either the Belkin or the Monster). I noticed a little bit of ground-loop noise, so I'll try and pick up an isolator soon.
If there's talk about a next-gen setup for iPods, I'd love to see one with the song name and title scroll across the display. I saw that the iPod code has been hacked, so it seems like it could be a possibility for someone with the know-how and the time.
Being able to use the radio controls to change songs would be OK, but I think it's easier to use the iPod remote - I can change songs there without looking down.
Anyway, sorry for the long post but thanks again for the work Jazzy! I don't think I could have asked for a better solution!