I have the D3X package currently and I'm decently happy with it. But there is a few flaws. Below are the only flaws that I care about.
#1 = The bluetooth does not automatically sync up with my phone when I get in/out of the car. I've watched a friend's F90BT do this with my own phone.
#2 = NAV is flash based on F90BT. No worries about scratched/lost discs.
#3 = iPod control is similar to D3, but F90BT has the "quick alphabet letter" sorting ability. Rather than scroll through 35 pages to get the the letter M, I can select "M" and move right to them.
#4 = iPod video capabilities on the F90BT.
The F90BT does have some other advantages such as SD capability and user customize symbols, but honestly I don't care about that. My bluetooth is nearly useless if I have to manually sync it up and enter the keycode every single time I get in the car. I figure I could probably sell my D3 with bluetooth module, add $150, and pick up a new F90BT off eBay. MY ONLY HESITATION is the fact that the F90BT boots up much slower than the D3. Depending on what source you last left it on, it could be a solid minute+ before you have access to change things. Is there a fix out there for this yet? Opinions? Anything I'm missing?