I had the Avic D series and loved it. Worked fine, Ipod control was crappy, XM Navtraffic was so so.
I now have the Avic F. Had it since last fall. Ipod control and voice recognition is great. At least 5-6 times per week when I turn the car on the F90 doesnt recognize that I have the Ipod connected. Unplugging the Ipod then reconnecting it usually solves the issue for that drive. Also, more often than not, I get Ipod sound only on the passenger side of the car. It may come back to the drivers side, may not. Its not a loose connection or bad cable. Many others on Avic411.com have the same Ipod issues I report. Also, no XM Navtraffic with the F90. Its MSN Direct. Old traffic info, gas station info and movie info is sketchy at best. I canccelled after the 90 days.
Other than Ipod functionality issues and MSN direct, its a decent unit for the price. Oh..one other step back. With the Avic D3, you can customize your boot up(splash) screen AND your background. You can only customize the splash on the F90, not the full time background.
Oh yeah...lots of phones dont work well (especially transferring contacts) with the F90. Its hit or miss often.