Windows 8 isn't dumbed down, at least on x86/x64 platforms. It's just different.
There are many improvements unrelated to metro, which is why they allow you to install on a machine that doesn't meet the resolution requirements of metro. Task manager & the file copy progress are much better for instance.
It may indeed have tons of architectural improvements under the hood - by all accounts it's quite snappy, which is always nice (and a rare pleasure for any version of Windows at launch.) However, the Metro UI absolutely is dumbed down - there's the inherent dumbness in trying to push a tablet/phone UI on a desktop/laptop environment, however nice of a tablet/phone UI it might be, but by many accounts there are things that are just plain stupid (they tried to kill Alt+Tab. They didn't
succeed, because of all the screaming, but the mere fact that they
tried should point to how wrong-headed they're being about serving the needs of Windows users. And the "Start screen" is quite frankly a massive, pointless waste of space in a desktop environment, but they're not giving you the option to get rid of it.)
I have no problem whatsoever with performance improvements - in fact, I am all for anything that makes Windows lighter and faster. I am less pleased at the attempt to move away from native code and the Win32 API and onto Microsoft's proprietary VM (primarily because any VM is a waste, but also because
backwards compatibility is half the reason I use Windows in the first place,) but for the moment they haven't ditched it, so I'll leave that argument until its proper time. What I
cannot tolerate is a bunch of upstart "designers" telling me that
I need to just get used to
them changing things on me because they need a prominent place to display their little art project, so that people will
appreciate it as is their due. Yeah, here's your appreciation, Metro Team: I'm not buying it. Not unless someone in management reins you in and makes your tablet OS entirely 100% optional on my
non-tablet. Period.