VMware's performance guys put Microsoft Vista through its paces on VMware Workstation 6.0.  The VROOM team says it works great!   

One of the great new features in VMware Workstation 6.0 is its Windows Vista support. Vista can be used as the host operating system (HOS) and the guest operating system (GOS) for VMware Virtual Machines (VM). The question to us is how well Vista performs in VMware Workstation 6.0. This actually contains two sub-questions. (1) What is the performance of Vista as the HOS? (2) What is the performance of Vista as the GOS? To answer these two questions, we did a comparison of Windows Vista and Windows XP performance.

To answer Question (1), we ran experiments using the same virtual machine on the two different HOS's (Vista and XP) and compared the results. We ran a set of workloads to measure the CPU, memory, disk and network performance of the VM. Vista host performance is on par with XP, except that Vista itself consumes more memory than XP. This means that Vista leaves less memory for the use of VM's than XP.

To answer Question (2), we compared a Vista VM against an XP VM both on an XP host. We ran the same set of workloads as for the Vista host experiments described above. While Vista guest performance is on par with XP in most of our workloads, we did find a few cases that perform worse on the Vista VM than on the XP VM. To understand why Vista was slower in those particular cases, we conducted the same measurements on native physical systems, rather than on virtual machines. We found that Vista is slower than XP on native hardware almost to the same degree as on virtual hardware. This made it clear that VMware Workstation 6.0 wasn't introducing any Vista-specific overheads, and that the relative performance on Vista is as good as on XP.

Read the entire thing, check out their charts, and then leave them a comment.  Go here.