GideonTech.com has posted a review on the RumbleFX force feedback headphone.
After getting into a 20 player game on GT's CS Server, this unit really stood out. I felt and heard each gun shot coming from every angle. I used to use a Koss headset to play CS, but it didn't provide any type of increased bass let alone Force Feedback. The Evergreen unit was sharp and precise in outputting the exact location of each noise movement.Read more
I also tried it while playing normal MP3s. After about 15 minutes of bass pounding hip hop and dance music, my ears were getting itchy! The vibrations may cause you to constantly scratch yourself, but you'll probably get used to it over time.