I like mine. 20-3G purchased April 2005. I actually use 'em in the truck so they get beat up pretty well and I won't blame Lightspeed too much for 'em breaking.
It seems both customer service and engineering are responsive. My first complaint was that the springs on the negative sides of the batteries were weak. Going bumpety-bump in the truck all day with the battery box clipped vertically made the negative spring that was on the underside of the batteries (the rh one I think) very weak, and occasionally the ANR would cut out for a second when it lost power.
I called them and immediately got an RMA number. However, I didn't send the headset back. I use it too often to be able to part with it for a few days! So, when the ANR finally quit for good in July, I stopped by their booth at OSH to ask if there was any alternative to sending it in. They handed me a new battery box on the spot, complete with installation instructions so I could do it myself (which I finally got around to last weekend - I will post pics later). Oh, and they gave me two new mic muffs and a new music cable too. Count me as a satisfied customer.
I just got the proper adapter for my cell phone too, but I can't get the cell interface to work. I can hear the person on the other end, but they can't hear me. When I hang up, there's about a 1Hz click in the headset as well. Very odd. I'll have to find someone with a 2.5mm phone headset so I can make sure the adapter itself actually works.
Still satisfied. The headset is VERY comfortable (I've flown 8.8 hours in a day with it and not felt a single ache), the audio fidelity is amazing, the noise reduction impressive (it reduces my truck to a mere background whisper), and for the price differential between the 20-3G and the Bose you can buy a second one and have enough money left over to take a friend flying for an hour to try 'em out. Sweet.