I took the maximo IP-HS5 iMetal isolation headset with me to WWDC 2010 this year, figuring it was a great way to test them out on both my iPhone and iPad. And it was. Due to "enhanced security" I had to be at the airport hours early, which meant hurrying up and waiting most of that time. Luckily I had a few podcasts and audio books on my iPhone so I queued those up to tied me over.
Now, low-bit rate talking isn't the best indicator of sound quality, but I have found many headsets over the years didn't handle just such low-quality talking very well. Some were never loud enough, many were never clear enough. The maximo ip-hs5 on the other hand did a good job. (In a fair bit of turn-around, I even used them to record both iPhone live! and iPad live! from on location in the hotel).
Sitting behind me on the plane were a pair of pre-schoolers who's parents biological creators lacked the custodial fortitude to ask them to stop kicking the chairs of those of us in front of them or screaming at the top of their lungs. So, I was also able to test out the iMetal's isolation and while I don't think anything under full blown cans could have drowned out the poor boundary deprived kids behind me, they did a great job of muting the overall ruckus.