I would have agreed with you before Metro/Modern showed that the UX designers at MS are a bunch of chumps. I will never forget my first experience of using Windows 8. It's the very pinnacle of anti-intuitive design. This is not just my personal opinion, but it is shared by
respected UX designers. In the console space, navigation of the current 360 dashboard is a slow process, far more so than the XMB. It looks prettier, but form vs function should trump all other concerns. Again, this is just MS shoehorning the Modern UI into every platform,
regardless of whether its suitable for it or not.
I boot up my PS3 and with one downwards press of the d-pad, I start browsing my digital games library. You have to jump through a bunch of hoops to do the same thing on the 360, and even then, it's slower to scroll through your entire library.
I can't see the Xbox One being any different, but its too early to see if Sony have bloated the PS4's UI or not. I hope not. The speed and functionality of the XMB has been consistent over the entire life of the PS3 and has been glorious.