I've a coupe (for a pi2) on my pi 3 and the only immediate difference that I can see is that the new pibows have the cut away for a cpu heatsink. There is no issues that I can see with the antenna for the wifi.
Improved access to the SD card would be nice as you need tweezers to get the sd card out, or to dismantle it.
Might have to pick a coupe3 for it next month.
