arisgoku2 :
Well the usb port is for a nas drive so even if it's not full usb 3.0 speed wouldn't it be better than a 2.0?
Sure. If you have 2 identical boxes, cost the same, one usb2, other usb3, by all means pick the usb3, but going back to your original request, and knowing what I know, I have stopped considering router-USB as a NAS solution, had stopped my research hence have no recommendation for you.
Oh I forgot to mention, another thing that drove me away was this particular router I tested, it couldn't deal with NTFS, it wanted me to format to exFAT.