Others say...

"Save your money"
I've noticed a consistant trend with Logitech products. If you buy their cheap/low end goods, you wind up with a pretty horrible product, whereas if you spend more money on one of their more expensive products, you usually get something great.
These headphones are definitely on their low end of things, and they fail to deliver. The 25$ you'll spend on these is 25$ too much. You will find you have wasted both money AND time ordering, waiting, and ultimately returning these.
Here are the ups and downs:
Pros: Almost none. The sound isn't completely horrible with these, but mind you, it's only passable. The cord is nice and long, and the remote built in to the cord is handy.
Cons: Horrible fit. These have a really poor ergonomic design, and I can't imagine them being comfortable for anyone. They feel as though they are constantly slipping off, and they provide poor ear coverage. There is nothing immersive about the sound or feel with these. The poor fit introduces pressure points on the ears and skull which quickly turn painful.
Normally, these comfort issues would prove problematic, except these headphones won't work long enough for you to worry about it. The microphone, I believe, has a manufacturing flaw which prevents a solid connection, rendering a staticy, unusable signal. The fact that the microphone is broken fresh out of the box is problematic. I experienced this on 2 different units. Occasionally it will work, only to quit working on a whim. I spent several hours tweaking system settings, only to realize and accept that the headphones were the sole problem, and that it was a manufacturing flaw.
In summation, these headphones are horribly uncomfortable and will most likely be broken within the first day (usually, straight out of the box). They are NOT worth 30, 20, or even 5$, as they don't work. Spend your money on a better pair. I'm sure Logitech makes some nice higher end headphones, but these are NOT worth your time or money.

"Pros and Cons"
These headphones are difficult to explain, especially when I hear a lot of complaints about them. It really depends on who you buy them from, perhaps.

Pros: The sound quality is great, the headset/microphone quality is smooth and my friends on Ventrilo can hear a big difference (better). Perhaps it's not as good as the top-of-the-line headphones, but for the price, it's absolutely worth it (I got mine refurbished). The headphones themselves are fairly comfortable for a while and they fit most ears. Your ears may feel a bit warm after wearing them for hours.

Cons: Okay, so I've had these headphones for some months now and they worked perfectly. Just recently, they started to break apart. Yes, break apart. The foam padding fell apart, followed by the microphone side, revealing all of the cords. I have to pop them back into place on a daily basis which takes about 5-10 minutes because it's very frustrating and complicated.

Overall, I suggest this item if you're a fairly active gamer, but they might disappoint some people.

Sound quality: 4/5
Microphone quality: 4/5
Durability: 2/5
Comfort: 3/5

"put your head in a vice"
I've been using this headset for about 3 months and I can't stand it. The wrap around your neck puts pressure on your ears and is not comfortable. The ear cups are so large, you won't be able to wear glasses with this set on unless you rest the temples on the top of the earpiece instead of on your ear.

The sound is ok and I like the volume control. I'd look elsewhere for a new headset.

"Broken in 3 weeks?"
I purchased this item about 3 weeks ago. I was very excited, it sounded great, my voice came over more clearly over the voice chat program I use for gaming, ventrilo. But 3 days after purchase the mouth piece mic fell off. It kind of snaps back in but falls off with any little nudge, but the microphone still worked. 3 weeks later the microphone stopped working altogether. I had to resort back to using my old desktop microphone.

The on-cord volume is kind of a pain to use also, as it doesn't turn very well, and I have to use fingernails in order to change the volume, not a big deal since I can adjust it on my keyboard, but kind of useless to me since I do use the headset while gaming, digging my nails into the volume nob to get it to work is distracting.

Next time I will spend a bit more money to get one that will last a bit longer.

"Works great!"
This is a nice headset. We bought one and tried it out. Liked it enough that we bought 3 more. (I have 4 gamers in my house) Affordable. Works great with Skype, too.