the telex 750 guys wear earplugs, the 850 works great, and is TSO'd

The FAA doesn't write the company manuals. If you company manuals say it has to be a TSO'd headset then anything else is opening the door for them to give you trouble. If you can take the FAA leter and send it up the chain of command, perhaps they will change their policy. Until then, the combo is a violation at alot of companies

I'm using the QC2/UFlyMike in the 900 and absolutely love it. As was said earlier, it folds flat, and has other uses such as for deadheads and commuting. Plus it's really lightweight and comfortable, I can wear it all day without it getting heavy or feeling like a clamp, and the headset and mic will all fit in the nice little slim case the Bose provides. I compared it side by side with another pilot's Telex 850 and the difference is more than obvious. Compared to the QC2, the Telex 850 didn't sound like it had any noise cancelling at all. Of course the QC2 does use a AAA battery, but I've been using it for a while now, and the claim of 35 hours on a single battery has been holding up as advertised, if not a little more. If the TSO issue is a problem at your airline, avoid it. But, I've used it with a fed in the jumpseat, and he never even asked about it. We have Telex 750s provided in the airplane (terrible headset), so if I get a fed with an attitude, I'll just put the Telex back on and suffer through that leg.

I have to agree the Clarity Aloft is the best headset I have worn. It's just as quiet as the Bose X but more comfortable and you don't have to worry about batteries.

I have the Lightspeed Zulu and really like it. I fly GA so the ANR and music input is nice and the bluetooth is helpful for FSS communications. If you fly a good amount of GA and are buying a headset anyways, I recommend it.

Clarity Aloft offers two headsets, and only one of them is TSO approved. Unfortunately it's been my experience that the TSO version doesn't work well in the CRJ, tons of feedback and cutting out.