I upgraded to Windows Vista Ultimate 64Bit when building a new AMD dual core machine.
Previously using Windows XP Professional on an AMD single core machine there were some significant changes mainly being based on the new platform code of the operating system and of course the visual layout.
Initially It was a little confusing discovering where administrative tools and other utilities had been relocated but for many people you should be able to navigate and familiarise yourself with the new system easily.
I have used Vista on my system for a while now and it does have its pros and cons due to some software compatibility and instability and some compatibility issues lying on the 64Bit platform integration.
Many people would complain about these faults and many others with Windows Vista though many people seem to forget and altogether dismiss that these same compatibility and instability issues were present in all of the previous Windows operating systems.
The previous operating System Windows XP has all these fault and with the numerous updates now is far more stable than the Vista platform and it is a shame.
This is mainly due to the numerous time consuming updates of which some do not cover the instability and compatibility issues which now nearing the release of Windows 7 the successor to the original Windows XP is quite disappointing no matter how much I like the visual upgrade.
I will be using Windows Vista Ultimate 64Bit for a while until I see the Windows 7 Ultimate 64Bit platform to have a completed Service pack updates and compatibility as I imagine on it's release there may be some patches and updates to come though hopefully it will be more stable.
Windows Vista Ultimate 64Bit
Easy to use
Excellent visual UI
Excellent new features
Excellent new tools and utilities
Poor disk defragmenter tools
Slow and numerous update releases