[momotomo]

Not feeling the issues with Win8, I'm on a low end Dell 13" and apart from the missing start menu I've noticed no real difference in usability.

After pinning everything to the home screen and task bar it's generally one click to get to most things (or Windows key -> Click) which feels more intuitive than Win7. Even the corner targets and new Alt / Win + Tab behaviors are solid enough. Was dubious about the quick app switch when you click at the top left but it's been unobtrusive enough.

The Windows Key + Live search on typing, while basically the same as the Win7 start menu search tool, feels a lot quicker in 8, maybe due to the metro search result style. Few other small bits like the new task manager are generally more useful as well.

The default fullscreen apps for photo viewing and what not feel like little horrors though, feels like a highjack when you click a photo and suddenly get dumped to a fullscreen app. Hitting escape does nothing and it can get a bit jumbled working your way back to the desktop (is there a faster return than Windows Key + Clicking desktop again?).

[bztzt]

Yeah, I think setting the default file associations to Metro apps is something that really damages people's first experiences with Windows 8 on non-tablets. I find it hard to believe that many people, even "casual" PC users, would prefer this setting, at least with the apps in their current state (which I doubt will change that dramatically by launch). It is easy enough to change (there's even a popup that appears the first time you open a file of some type, asking if you'd rather use a different app) but a standard rule of UI design is that most people don't and defaults do matter.

[momotomo]

I think if someone's running a majority of metro apps it might be a bit less jarring (because they are used to the "app as the whole screen" thing), but it can be confusing when switching, and the switch feels a bit like everything else has "closed" if you're used to the task bar. The windows key acts as a good anchor though, everything feels pretty close at hand.

I do like that quick little context box for the other installed apps. Advantage to how that app selection context box works is that it scales with the users expertise - if you do see it, it means you've installed software, which probably means you understand why the selection is necessary. Average mum and dad user probably won't come across it / get confused by it.