I use a kenwood X994 in a HUmount flushmount install kit with a custom ipod dock i made to fit in the cubby behind the shifter. Do it right and it almost looks like it couldve been a factory option. Best parts about the headunit are the multi color screen and buttons, bluetooth calls and streaming music, full ipod control or any usb device like a flash drive, and both the usb and the headphone input are in the back so you can make it even more stealthy. I was able to wire in a headphone input to the center console that also looks kindof stock. Plus the sq is incredible and it puts out an impressive amount of power. Keep in mind those are opinions
This one has a full 5 band equilizer, and itll support a usb HDD but it can only see a maximum of 256 folders in one device i think, im not sure if that will help or not. It also has the ability to do direct crossover from the headunit. So if u want to block certain lows or certain highs, and it also has settings for each speaker size and where its at door/dash/deck, as well as how far each one is in inches from the center of the car. I dunno if thats impressive or not. But being used to cheapo Dual stereos and the lower end Alpines i think its pretty impressive. The only issue i have is in the cold weather the screen transitions aren't as crisp but the second it warms up its back to normal.