Benchmark results availlable?

I wonder if there are any benchmark figures available in which the performance of Pianoteq with respect to OS is considered. I'm quite aware of the fact that performance depends on much more such as Soundcard and VST Host.

At this moment I've to make a decision on which OS to use:

- Windows XP? It's not quite new but there are lots of experience and  papers on it on how to tune it
- Windows 7? Is quite new but better support towards the future
- Ubuntu? Free, but more for the advanced (technical) user. But I also noticed that most of the hardware vendors supply specific drivers for windows (and MacOS).
- MacOS? No, I need mac-hardware for it and I like to build the solution myself.

Main concerns are stability and performance because it is going to be used live. Why this concern? It is something that troubles me: I've run Pianoteq with vsthost and cantabile. Both will crash when the samplerate is put to 192kHz. Pianoteq itself, as a standalone application,  runs fine at this rate.....but I like to run multiple instances of Pianoteq.