I broke down and bought my first Vista machine last Sunday, an HP Pavilion from a local box store. From the outset I was underwhelmed by the performance of this system (a 64 bit system with 4gb of RAM), which should have been screaming but wasn't quite. My 3 year old Gateway was running circles around this thing.
So after a few hours of removing what can only be described as factory-installed Crapware, this state of the art machine was still dragging. I pinged my local SQL Server user group to solicit some recommendations which proved to be quite helpful. I shut down the search indexing feature, ran a full defrag and bought an SD card to enable ReadyBoost, and these changes finally brought my system to an acceptable level of performance. A few further tweaks and I am finally satisfied that I'm getting my money's worth.
On a positive note, I did not have any issues installing SQL Server 2005 or 2008 on this machine. I had read of some early problems with SQL 2005 and Vista compatibility, but I did not find any problems. VirtualPC 2007 runs well after installing machine additions on my new VM - I had been using VMWare for virtualization and was unaccustomed to this step.
So for now, Vista and I are getting along well. We'll see how it goes.