I bought these Sennheisers about a year ago, after owning numerous PC headsets over the last decade. These were recommended by a pretty regular group of gamers I've talked on voip with over the years. They sounded very clear, and I heard the sound quality of the headphones was pretty good, so for 50 bucks I said why not.
As it turned out, after about a year of owning these now, I will say that the sound quality of these do beat most of the competing headsets you'll find in the price range. Sennheiser does make a quality product, but only to a certain degree. The sound quality, as I've said, is obviously top notch. Coupled with a good sound card, your ears will be happy.
As I said though, the build quality is good to a degree. After a year of owning, the microphone is now starting to fail. I need to wiggle and move the microphone up and down and push and pull until it stops making heavy static, and hopefully I can get it into a position where the static stops in under a few minutes.
But hey, for the price, I got a good year of daily use out of a nice product. If it were more money I might be really upset.