Unbelievable, how many people always say, their product is better, faster and less "whatsoever-taking" than the original...

The sidebar uses 50% less RAM and is faster than the original Microsoft Sidebar with more extras and works on Microsoft Windows Vista and XP

There will be a clear and good reason why the one from Microsoft itself uses a bit more. Maybe because it simply fits into the system as it should...? Also:

Thoosje's Vista Sidebar is also part of the Vista Transformation Pack that turns your XP OS into Windows Vista.

That is simply wrong. The best it could do is to suggest that you are running Windows Vista... but it will still be Windows XP. Why do people always tend to lie??