But only to a point. Anyone who knows computers knows that just because something works or performs in a certain way on one computer doesn’t mean it will do the same on another machine. Forums are full of posts where one person is having a problem that someone else hasn’t. So before the laptop checking crowd get too tired from patting themselves on their shoulders. 
may I make another suggestion? Another way to prepare for a new o/s and check your solid working system at the same time is by the use of removable hard drives. Buy a bay, and two drawers. Your solid system o/s drive goes in one drawer and a new drive with Windows 8 goes in another. Swapping drives takes less than 30 seconds. And it’s a lot cheaper than buying a laptop. That way you can test all your hardware in your working computer with Windows 8 and make a proper assessment of the hardware yet not affect that rock solid system drive in any way. What you can’t do with that approach is test some of the libraries easily and you don’t want to change anything on the other drives, so one has to know what they can do and can’t do, but when it comes to hardware, I suggest this approach always beats testing on another computer. Of course, it depend too what one wishes to test. Do you really want to see if audio interfaces have drivers that work etc. or do you just want to explore how Windows 8 itself works in general? What one wishes to do will help one decide the best approach for them. My point is though: what works on a laptop may not on a desktop and vice versa, so it’s always best to state what it is you are testing before making blanket statements. Just some thoughts.