Turn off the Aero stuff in Win 7 then for gods sake - yes - it is that easy. The Start button in Win 7 is finally a functional button. When compared to XP - the Win 7 Start button is a correct and fully functional Start button.
I personally hate the Win 8 screen - I would have to use Classic Shell and if I would have to do that to get a good OS - then I don't see why I would even want it.
Turn off Aero? That has NOTHING to do with the ugliness of Win 7 GUI. Win 8 DESKTOP GUI (not Metro) is great. It is sleek and fast looking. Very nice. Win 7 GUI with or without Aero (I had Win 7 beta on a virtual machine so no Aero) is awful...fat and bloated looking..rounded, swelled up bloated looking corners. I believe Microsoft said it was that way so it looked "3D". It just looked fat, slow and bloated to me. Win 8 has square corners just like XP and earlier.
Win7 "looks slow"? (That's about the strangest thing I've ever heard said about an OS.) XP has rounded corners BTW (at the top--very visible).
Win8 is Microsoft's worst brain fart since WinMe. (Vista barely registered on the M$ Phart-o-meter.) I mean, if you want to put the Windows Phone OS UI on a tablet, then go right ahead; that even makes some sense. But on a desktop? ...that's just the dumbest thing that they could do.
Bob. Clippy. The Ribbon. And now... Win8. For every NT, XP, and Win7 that M$ comes out with, there's an equal & opposite utter failure. Well, maybe this failure will be yet another learning experience.