I just sent my LS Zulu 2 in to have the mic boom repaired. Seems to be a common problem with the headsets. Interestingly, when I spoke with their customer service rep, the gal asked if I put the mic muff up against my lips when I used the headset, and I confirmed that I did. She told me that is an incorrect way to use them, that the mic was designed to sit away from the lips when being used and that if my voice wasn't being picked up then I should adjust the mic gain switch. As a result, people tend to pull on the boom so that the mic muff would sit in front of their mouth. Okay, made sense, especially since the boom did appear to be a little short, which resulted in me "stretching" it to ensure the mic sat centered over my mouth. I still had the original box and instructions that came with the headset when I bought it three years ago, so I pulled out the instructions and read through them. It said to place the mic 1/8 inch from the mouth. Which is really saying put it as close as possible to the mouth, like other headset mics. No mention of the mic being designed to sit away from the mouth.
Anyway, their customer service and five year warranty is fantastic. But if I had to replace the headset, which I will eventually, I would look at a pair of DC's instead.