Plantronics DSP500 Headset

[L8CS]

I'm looking for a good quality headset and came across the DSP500's. I want to use them on a SB Live Platinum and wonder how they compare to analog headsets for gaming. They're also digital, so they use a USB port instead of the analog inputs on the SB. I rather use seperate headphones like the Grado SR-60 or the Sennheiser HD495, but I would need some kind of clip on microphone setup. Any ideas?