I have been using Windows 8 on my laptop for about 2 months now and I have one recommendation: AVOID THE METRO START SCREEN ENTIRELY. Windows 8 is being officially released on Friday, hence this post.
You can basically disable it by never using it nor never pressing the 'Windows' button on your keyboard. From Metro, you should have a desktop tile, just click that and never open Metro again. Yes, I have no Start button in the new desktop view, but who cares. I just set up my desktop and taskbar to have the programs/apps I use ready to go. If you avoid the Metro interface, Windows 8 is just Windows 7 and works flawlessly. Metro and the Windows Store are worthless in my opinion and I love cool fun things, but it is just a waste of time and doesn't belong on a desktop machine.