With SP1 Vista has really improved. I hated Vista at first as well, but unfortunetly at some point you wont be able to buy a new machine with it, and with server 2008 out now you are going to have to move over as they are build off the same kernel and it helps if you know the Vista UI. XP sp 3 probably was the last straw for that OS as well so support will go away sooner rather than later.
dont get me wrong. my gaming rig at home is still hp, but my work machine is now Vista.