Vista if you have a decent enough computer (2gb ram at least, 2.4ghz core 2 duo) then no its fine itself. but people have had problems with drivers and software compatibility. If you have less than 2gb ram then no i wouldn't recommend it as your computer would run slower than if you had xp.
If you are just using it for work/internet/chat/light gaming, etc then vista will be fine with 2gb more ram.
If you are using it to some hard gaming, then i would recommend xp UNLESS you have a GOOD graphics card (8800gt and better) and 4gb ram.
But if you're comparing it with a Mac thats a different matter.. if you're not used to it, macs will be odd at first, though you'll get used to it.
But if you're not gonna be doing any photo/video/music editing, then you might as well get a better laptop with vista.