Just got this in this week, and gotta say I'm loving it. Ordered mine off amazon for $349.99 with free shipping. The screen quality is all I could ask for in this price range. It has built-in bluetooth that syncs up great with my phone. Has USB/SD/Aux all on the front. I added the HD module for 80-90 dollars off amazon, this is my first experience with HD Radio in my car and I love it, can tell a big difference between HD and regular radio. All the stations I listen to have great signal around here, have never dropped to regular analog radio vs HD.
The USB is very fast, it's nice going from a single-din with USB to a double-din as it's much easier to navigate the flash drive.
The sound quality is one of the better sounding unit's i've had. My old unit was a JVC KD-r900 and I can tell a good difference between the two. I'm glad this unit has 4v preamp outputs, as that was one of the features I was looking for in a double-din as many have 2 or 2.2v.
I plan on adding the navigation eventually, I just wish it wasn't so expensive. For $200 you can buy a great GPS Unit, so it shouldn't be so expensive for a module box to add on to it in my opinion. This is one of the only down-sides of this unit.
As I mentioned above the screen quality is great for a 5.8" double-din screen that's under $400. I can watch DVD's on it and it also supports DivX which is nice too. It allows for custom backgrounds and downloads them off a flash drive or SD card so you can remove it and keep your background. If you switch to HD Radio and back to USB it resumes where you left off, an obvious feature that some units seem to be missing.
It seems that you can make some animated backgrounds as it has some stock animated backgrounds, even an EQ background. I'd like to see what's involved in tweaking it to have your own customized EQ background, it will take longer until I'm able to figure this and my next point out however.
It appears that this unit may support "Custom applications" but I can't find any information on it in the owners manual.
Here's a pic of it installed in my car, cellphone quality.