What Microsoft tends to do is make their OS more "pretty" and userfreiendly if you may.
If you are trying to run a business or an email/company server, DO NOT use Vista. It has been proven that it has performance problems.
If you are just using a laptop or just using like Microsoft Word or something on your PC then Vista could be for you. Userfriendly and "pretty" but nothing special in terms of performance rates and that.
And yes Gorman it does take up 40gigs on yo system for Vista OS alone, because they have tried to add nicelooking apps and such, instead of focusing on making it more streamlined.
If i am not making sense then i am sorry, but i am very very tired.