Howard all the way.
if your worried about not having a front USB, dont fret too much about it. Normally when you have a dash mount kit for your head unit, there's a hole somewhere in the storage compartment and you can easily put the usb wire through and it'll be a nicely hidden usb. Here's an example of how mines look like.
Advantage of this is your USB's life will be extended because its not exposed to the hot sun all the time (i have had usbs die that way) and the display on the head unit will be bigger due to the extra space. People also generally dont look inside that hole, you only see something in there because of the flash on my camera, normally its totally hidden. When i'm using the usb instead of SD slot, they have no idea where the source of my music is comming from. Most think i have some fancy subscription. Having the usb in the front makes it look kinda cheap headunit wise. It would have been cool if they moved the aux to the back too and made the screen even bigger. I'd prefer a bigger screen to having a usb sticking out like a sore thumb anyday.
My head unit also has a SD card slot reader up to 128 gigs for those extremely bloated lossless files. However, this head unit is soo **** good that you really dont notice too much of a difference between mp3 and flac since the digital audio convertor on this head unit is really great.