I actually like the start screen:
Good:
- pressing [START] brings it up, I can start typing, and it filters like the start menu of old
- when filtering, the categories always appear in the same place
- meta options are big and appear in the same place (makes a difference at 2560x1440 with standard DPI)
- It doesn't overlap or clutter the desktop -- I press [START] and see a new screen with bigger options that are easier to navigate
- to me, the general windows desktop theme (flat, pastel, simple) is a huge improvement (reminds me of 3.x a little in that regard)
Bad
- It's not intuitive or obvious, I guess, that the [START] search functionality exists at all
- It's not obvious how to do meta actions (open with, for example)
- at first blush, if you make it to the desktop, it's not obvious how you get back to the start screen
- the hidden menus are obnoxious if you're trying to remember where they are hidden
- the "docked" apps or whatever, where the fullscreen app can take a portion of the screen, are worthless
- the hand icon, used to "discard/close" apps, is kind of weird on the desktop (I can discard my desktop? lol).
I dunno. Overall I am indifferent. I actually applaud Microsoft for giving something a go, I just hope that they keep working on it to make it more intuitive and less "post-pc"-ish (which is pretty insulting when I'm running it on a PC). I don't really use the tiles, and I'm on the desktop 99% of the time... so. Yeah. From a ui perspective alone, I don't really find it that abrasive.