I have a Sierra set, which is the second headset I've owned. Overall, I think they're great; the ANR is fantastic and they're comfortable on my fat head. But I don't exactly have a wealth of experience to compare them to.
One thing I can say for sure is that Lightspeed's customer service is excellent. My first set was a 15xlc I bought used off eBay. After about six months of usage, one of the cradles failed. I took the set apart and determined I could do the fix myself with the replacement part, so I gave Lightspeed a call. First nice thing- a person answered the phone. No automated system, press one to speak to a rep, etc. I explained what had happened, and the rep proceeded to ship me a pair of new cradles for free. Didn't ask how old the set was, whether I'd bought it new, anything like that. Just boom, free parts.
It was an easy decision to stay with them when I was read to upgrade.