I've found the POI database to be spectacularly bad. The guidance actually works pretty well and has some features that are better than Google Nav. But the downside is, like all in-car nav, it's not a garmin/google nav and it looks like garbage. It attempts to mimick street signs, but the dimensions are all off and the fonts are strange. The bubbles with street names are in MS Sans Serif. The streets lines are way too thin to really be able to look at properly at a glance. Compare a Garmin which has exact replicas of street signs, speed limits on most roads, good look maps, etc. That said, I have seen far, far worse looking in-car nav. I still haven't figured out what the red/yellow/green arrows along side the route are. At first I thought it was supposed to be traffic, but if it is, it has no correlation to reality.
If I could rig something up so that I can press a button on my steering wheel to activate voice commands on my Droid X, I can't imagine I'd ever use the in-dash nav again. You just can't beat the power of Google and the internet. It will understand everything, making any standalone product always disappoint.
My dream is that Google will buy Garmin and then partner to make in-car infotainment systems...