... so just a tip for anyone else looking to make the same move:
Don't.
First of all it's an analog headset + a USB adapter - which isn't a particularly bad thing as long as everything works.
Too much white noise in idle - the USB adapter isn't matched correctly to the headset drivers. To up the presented impedance sufficiently to counteract the white noise results in too low a volume. The 7.1 is as bad as the Asus Xonar / Razer Surround / etc implementations. Whatever synergy there was with the G35 = a lot better. Also headset is a lot more lightly built, and the headband is kinda crap, putting too much pressure on the top of the head in comparison to the 35.
EDIT later impressions: Actually sound is not bad when paired with a USB adapter that does match the drivers more. Still have issues with top of head comfort but it's diminished somewhat. Still think the G35 is a better buy tho in comparison.