Pros: As the description says, provides the most utility out of any other headsets we purchased and tested.
The variety of ear pieces, ear clips, and wearing styles allows for the utmost comfort regardless of who is wearing it.
The audio quality is clear as expected (tones sound very natural) and the microphone clarity is crystal clear. We were able to test the microphone clarity among other plantronic devices and this was certainly the best of the latter.
Not to say the quality isn't one of the biggest selling points, but the comfort of this device is actually #1. This was really well designed to ease pressure at all points of wear, fits snugly, and never gets hot despite it's snug placement. You absolutely forget you are even wearing it, and we wear similar products like this ALL day. This is by far our favorite.

Cons: None! We really couldn't find a single problem with this device. It comes with 3 different ear loops, 4 different gel-like-plastic ear bud pieces, and 3 different wearing styles. Comes with a charger and even a travel box to throw it in(about the size of a glasses case)! How nifty is that?

Other Thoughts: We have tested a bunch of similar pc microphones around this price range. This is our #1 pick. We plan to purchase 6 more (4 already on their way) and use it throughout our office. No wireless interference. Just plug the usb receiver into your computer... that's it! Drivers download automatically and it's ready to use! It was ready to go before we even sat down. Started a call out through skype 2 minutes after the product was delivered to us. Great stuff!