Im with LC in the fact that Vista is very buggy, ive personally installed vista on a few computers and bought one computer with it pre-installed.
The laptop i bought came with Vista already installed and we have not had any troubles except u need to reboot every now and then to free system resources. On the other hand my main desktop which i use most of the time i removed XP a few months back and installed Vista and had nothing but problems.
Ive done alot of research into PDA's lately and im going to get the new Blackberry Bold when it is released in Australia in the next few weeks. Apparently it owns all
im not a fan of the iphones and their more for fun use anyways, Blackberrys are better for business's