I got a new dual core Laptop with VISTA pre-installed -- I found running WK6 with an XP Host not too good. The main problem was after shutting down a miniSAP system on the Win XP guest the host hard disks would just spin and spin and spin for around 10 minutes --Think it's something with VISTA's "Optimisation" routines.
Even after powering off the VM and shutting down WKS6 the disks would spin and spin --nothing else running on the host at the time.
(The SAP application has a quite large DB - using MAXDB)
With a bit of research and some slipstreaming of SATA drivers etc I managed to "Downgrade" my new laptop to Windows 2003 Server Standard edition.
I tinkered with it as per http://win2k3.msfn.org to make it suitable for a workstation rather than a server. Now IT FLIES and so does the XP VM.
When I shut down the VM or even WKS 6 itself I don't get ANY extra disk activity now on the HOST.
On W2K3 host the Guest VM (512MB) is running IMO at almost native speed.
I'm running this on a Philips Freevents X59 laptop (one of the very small portable but powerful dual core laptops).
I'd recommend wherever possible if you are running a HOST VISTA system on a laptop to "Downgrade" to W2K3 or Windows XP where possible. My W2K3 is a student version so didn't cost anything but XP will also work better than VISTA on a smaller laptop.
It takes some work as you need drivers for the newer SATA disks and video accelerated chipsets but these can then be slipstreamed into an XP service pack 2 system and a bootable CD made. Use the nLite utility for this and drivers for almost every known computer on the planet can be found at http://Driverpacks.net/DriverPacks.
Most laptops don't have floppy drives and in any case pressing F6 to load drivers at Windows install time doesn't always work either.
In conclusion WK6 on my system really flies since I removed the pre-installed VISTA Home Premium.
The time and effort invested was WELL worth it. Now I have NO trouble at all with running all sorts of VM's on the laptop -- not concurrently due to the RAM and processor limitations of the laptop. Most of the VM's are loaded from an external 500 GB USB disk --also no problem here either.
So after initial disappointment with WKS6 I'm really impressed. Vista was the dog not WKS6.
Cheers
jimbo45
