I installed the GM 2006-12 unit in my 2006 Impala. It has a ton of features, but not all are executed very well. Let me know if you have any questions.
-Micro SD card for MP3s and Movies
-Plays CD, DVDs, and Data discs (MP3s)
-Bluetooth (for phone calls or music transfer)
-Rearview Camera (cam not included)
-Big screen with decent picture
-Lost of input/output options (ipod, video, aux, usb, etc)
-Fits nicely and looks good in car
-Navigation map is outdated, takes weird routes, and would be costly to update (only use as a backup not primary GPS device)
-Touchscreen is not very responsive and can be sluggish
-User Interface is very bland and not easy to navigate while driving (radio is fine, but browsing SD card is tricky) Small complaints like clock doesn't show while playing MP3s from the SD card.
-Requires extra components to fully integrate with car (warning chimes and steering wheel controls)
-No installation instructions included, just a basic wiring diagram