Well i'm on Os 2.7 and it runs like a dream. But as i'm sure you are aware it will only get better. at the moment there are only three channels via usb and two via audio although you can have up to 16 different sounds coming from her at anyone time.
I'm using her in Cubase SX 3.1 and I can't stress how amazing this machine is.
It comes loaded with 512 bass patches
768 lead patches and it's all sorted into the following catergories -
Acid, Arps, Bass, Classic, Efx, FM, leads etc so it's quite easy to navigate your way around and the modulation capabilities are sick.
And the envelopes are amazing - so responsive it's crazy.