Pros Comfort, Boom Mic (not in-line)
Cons none, yet... durability might be an issue with the swivelling parts htough
Summary I've gone through many (3 so far) xbox live headsets from microsoft. i broke down and bought a Jabra Ear Boom headset built primarily for cell phones, and while the molded ear buds were initially comfortable, i found that over extended periods i would have to switch the size of the bud i was wearing.
after using this plantronics set for an afternoon/evening of gaming, i never had to adjust it once, and sound clarity was a big improvement. Teamates also remarked on how much clearer i sounded with the new headset.
If you have the need, and the means for this headset, i would highly recommend it!