Call me crazy, but from all the videos and photos I've seen, I think HTC hit a home run with the design aspects of the 8X. In regards to the black areas on the sides, I don't really see what you're talking about.. they look the same width as on my Lumia, and on the images of the 920 as well.. nothing different there, maybe try a different image?
http://i-cdn.phonearena.com/images/p...-Lumia-920.jpg
If you look at the 920 enlarged you'll see that it has the same black space on either side of the tiles, and the same amount as the 8X here:
Windows Phone 8X by HTC Overview - HTC Smartphones
In some renders, NOKIA made it so you can't differentiate between the black screen and the black background on the home screen, making it seem like there's no gap.