I have been using PC Pitstop to benchmark my rigs in the past and I do believe that their benchmarking formula is accurate. As you know, many of the new laptops are still pre-configured on Windows XP especially netbooks but the majority of the desktops and laptops comes with Windows 7 Home Edition.
I had the opportunity to benchmark my laptop using Windows XP Home Edition, Windows Vista Home Edition and Windows 7 Professional Edition on PC Pitstop. An advantage of using PC Pitstop to benchmark your computer is the ability for you to save all your previous test results so that you can go through it later when you want to.
To my experience in the past, I find Vista quite stable but it has a major flaw - You need to have a decent combination of cpu/memory/hard drive/graphics card to be able to experience the full aero effect. Using PC Pitstop's benchmark on my laptop running Vista with SP2 returned a score of 4344. A typical value for my laptop's configuration would only have a result of 4076 so my laptop is in the lead with 4344.
Using Windows XP with SP3 returned a score of 3709 which is below a typical score of 4076! That is just sad. Windows XP is fun and agile but it has two major flaw - It does not support DirectX above 9.0c and the API is not doing its job as compared to both Vista and Windows 7! It is not a problem for me if Windows XP does not support DirectX 10 or 11 (presently) but I am finding the fan noise on my laptop simply unbearable!
I then load up my laptop with Windows 7 and ran the same benchmark again. Guess what? PC Pitstop returned a score of 4220! That score is even lower than the score when I had my laptop running on Vista! That is simply unheard of. I thought that Windows 7 is supposed to be even better than both Windows XP and Vista!
To be fair, Windows 7 is an upgraded OS from the previous versions and I quite like to use Windows 7. However, there is a problem with Windows 7. I'm sure that you all will know that since it is a new OS, many old softwares will not be able to run on it. If that happens, not to worry. What you need to do is to buy Windows 7 Professional version and above so that it will allow you to install virtual Windows XP on your Windows 7. Sound cool, isn't it? I have tried using Windows 7 with Windows XP mode but it will not allow me to update my Nokia's firmware. It requires either XP or Vista, both 32 bit and 64 bit. What a shame, isn't it?
In the end, I ended up using Vista all over again - Thanks to Dell...