I'm currently testing the Demo of DP8 on my Windows-7 x64 system (QC 9400, 8GB, SSD, Focusrite Saffire Pro 24DSP).
My primary DAW is Presonus Studio One and sometimes I'm using Pro Tools, that was my choice until I've switched to Presonus.
I never had contact to DP before, because I'm not a big fan of the Mac OS. But now with the release of the Windows version, DP comes closer to my interest.

My musical work is orchestral composing for film and other media and it seems DP have some very nice features to work with in this area.
But my current problem with DP8 is the audio and vst performance. This seems very bad und makes DP8 nearly unusable to me.

CPU consuming is very high and I got many drops und 100% CPU peaks. It's about 3 times worse as in Presonus S1 or under Pro Tools 10.
For example, I've transfered my current work on a small project from Studio-One to DP8. A very small orchestral mockup with about 14 instrument tracks, most of them in NI Kontakt-5.
With a ASIO latency set to 256 sample buffers this plays in Studio-One with CPU utilization about 20-40%.
The same instruments, the same MIDI data and the same vst plugins in DP8 causes the CPU to work nearly 80-100% and often the processing meter goes to red that causes many drops, crackles and sound distortion.
I also tried only to play 20 audio tracks without any plugins and this utilized the cpu (DP process only) between 20-30% with peaks up to 80%, that also seems a little bit high to me.
Maybe DP8 has some strange problems with my audio interface (Focusrite Saffire Pro 24).
DP8 seems a very nice and highly featured DAW, but with such performance issues it makes no fun to work with.
I hope MOTU will address such issues in the future and work on a more stable and even faster windows version.
Maybe I think about to write MOTU support with that issue.
regards
Markus