i for one prefer usb, ipod cable from the back of head unit leading to cubby hole up top. i hate seeing wires

 

yah, but if you're not a ipod user like me the front loading USB and SD card is a nice touch. on my 3100 i have a tiny USB drive on it... check out the size of this thing.

but obviously the 3200 has SDcard slot so dont need this...

 

I prefer rear aux/usb ports too, you can make them come out wherever you want for a much cleaner install.

 

I like the look and how clean the aux/usb in the rear is, front is easy though, just a little in the way