I always felt the standard 16" were just a bit too small (aesthetically)
Chris Bangle agrees with you - it's something he was quoted as saying in a recent magazine article. I think the 16s look OK on original coupes with black sills, but with the LE/plus kit I think the car needs bigger wheels.
Those 19s do look the business!
Incidentally, I was parked next to a new Jag F-Pace recently that had massive 22 inch wheels. My coupe looked like a toy car by comparison. It reminded me just how small the coupe is by modern standards.