I ran Windows Server 2003 as my desktop from the time it came out until Vista shipped and now I'm on Windows Server 2008. And boy does it rock!
I won't repeat the many blog posts that are out there that go over the steps needed to get Win2k8 running just like Vista (though I will refer you to my last blog post about getting sidebar working right). What I will tell you is that almost everything runs under Win2k8 with less RAM than under Vista. People will tell you all day that there is no difference between the Vista SP1 and Win2k8 binaries but there is a difference somewhere.
Actually I checked the ntoskrnl.exe binary from both Vista SP1 and Win2k8 and they are truly exactly the same. However, that doesn't mean they run the same. The Vista kernel could have all sorts of compatibility shims that get loaded dynamically or checked at runtime. One piece of evidence that Win2k8 is different is the fact that a few programs don't function correctly. The latest version of skype and microTorrent do not function (you can use an older version of Skype though).
What I know is that it *feels* tons faster. IE just appears instantly. Explorer windows open immediately. And the RAM usage just speaks for itself. The table below shows what the memory usage typically is on my system for
|Application||Vista SP1||Windows Server 2008|
|Desktop Window Manager||40-50 meg||756k (yes, k!). Part of this is the fact that I have not yet been able to enalble taskbar video thumbnails.|
|Sidebar||25 meg||12 meg|