Got my new G930 headphones last week. They're pretty amazing!
This wireless alternative of the G35 connects via a docking station, which is connected to the comp by usb and connects to the headphones via micro usb. On the docking station is a usb wireless receiver which is set at the frequency of your headphones (ie not someone else's G930, but I imagine if you sync'd with another docking station, it would work the same).
The headphones obviously use the micro usb to charge, but you can still use them while charging. So even when power runs out, you still have usb headphones akin to having a G35. It uses a lithium battery inside the left (I think) headphone. It's also replaceable! So if you like, you can keep another around for emergencies. The time to charge is about 2 hours from absolute dead, and the battery lasts around 10 hours (the status screen has a charge level).
Comparing to my old G35, there's not too much difference (apart from the 930 being wireless) in quality or options available. A few extra voice morphing options have been added and you can play around with the 7.1 surround a bit more (ie changing volume and other options for each speaker). Other than that, the sound quality is retained whether you're using usb or wireless.
The range on the headphones is pretty impressive. The box says 12m, but I reckon I got about 15m before it started dropping out! Not that you'd need to be that far, but it's a nice-to-have.
One drawback I've noticed is while I was at a lan. I'm not sure if it was interference or high CPU usage, but occasionally while I was watching things during the lan, it cut out every now and then for as long as 10 seconds. It works perfectly at home and I haven't tried it on games just yet, so here's hoping it was just interference from lots of other signals.
A quick note on cost. Depending where you look, prices vary from about $120 up to a massive $250! So really shop around. I got mine from ebay (a logitech reseller) brand new for around $130! Which is around the cost of the G35 on ebay as well. So depends what you prefer, but wireless headphones are very convenient!
The G930 is probably the most stable set of wireless headphones I've ever owned! Despite the couple of drop-outs I got at a lan, it hasn't cut out or lagged at all. The 7.1 surround sound quality is as good as the G35 and there are a few extra options to play around with. It has a great range, doesn't take long to re-charge, and is cost comparitive when compared to it's wired counterpart. So basically it comes down to whether you want wired or wireless. Your choice!