I currently have the F-90BT and have been relatively happy with it. I'm considering upgrading to the X920BT for a couple of features, including PandoraLink. I've read the marketing material, but I wondered from "real world folks" if you think it would be worth it? My current F-90BT is modded quite a bit and from what I understand I will loose that option with the new unit. My hope is that the voice recongnition will be better (I find mine unusuable right now), quicker boot time, better integration with my iPhone4. Thoughts?