Well after about 3 hours of setting up steam and Uplay accounts I finally got about 30 mins play time in!
The memory overheads on this are crazy, Uplay (ubisoft DRM) uses almost as much resource as the game itself!!
Anyway the gamer itself so far is excellent, im still having some lag issues, i.e. you hear the note you play a few milliseconds after you actually play the note which is a bit naff -I've got a creative soundcard with analogue out to a power amp which my speakers are hooked up to. I hear its worse if you use audio over HDMI to TV as the TV adds extra audio processing lag.
I've made some improvements by manually editing some .ini file settings I found online to reduce lag, buffer size and some other stuff, it's a bit like overclocking in that respect, trying to balance stability and performance of two or three options without crashing.
There is still an annoying bit of lag, the next step I think is to revert to my onboard audio instead of my soundcard, as my sound card has no onboard memory and it should take some processing overheads out of the chain.
If I can eliminate the lag to an extent where the sound delay is more like playing normally then I'll be very happy, its not too far off now but noticeable to the point you've not only got to think about what your playing but play slightly ahead of the track to compensate for the audio lag.
I had to invert the tab as I couldn't get my head round the standard GUI tab thing.
Otherwise excellent so far, my forearm is aching from playing the kinks!