I hope this is the correct area of the forum to bring up this question.

What are your experiences using different Virtualization Applications (KVM-QEMU, Virtualbox, VMWare, etc.) using Windows under a host Linux OS?

My experiences:

After watching the benchmarks posted on the main Phoronix news area about how KVM usually performs better except with graphics, I decided to give it a try this time. (I was previously using VirtualBox.) Current machine is running Kubuntu 12.04.

When using KVM-QEMU (through Aqemu front-end) to install Windows XP integrated SP2, it took at least 90 minutes. When using Virtualbox, it took only 20 minutes to install, maybe less. Also Virtualbox was dramatically more responsive, whereas KVM so far has been a bit slow. I was using the default settings in both applications and didn't change anything.

So far I'm am a bit surprised at the differences I am personally seeing. I have not tried running Linux to compare between KVM and Virtualbox, but I might soon.