I do work for Bose, though it's a different division than the one that makes the consumer electronics. I do very industrial stuff, but it is definitely the same company. That being said, I am not a Bose wonk by any means, and I am picky about what I like.
First impressions: the cable is too short. It's probably the perfect length if you're listening with an iPod or some other form of personal listening device that is attached to your body somewhere, but as I'm listening from my work computer and the plug is on the back, I'm a bit constricted in my movements. This could easily be solved by an extension cable, so it's a minor annoyance.
The design is a bit different than the "earbud" type of 'phones. It's a little bigger, and it has a soft silicone piece that fits into your ear canal. It doesn't fit tightly-- part of the design-- and the main piece fits in your ear. It's actually pretty comfortable and not distracting like some of the earbud designs I've had in the past.
Sound quality: surprisingly good. They're not world-class headphones, but they have a good, solid sound and enough detail that I can hear subtle things like the buried guitar voice in Rammstein's "Los", and clear guitar string attacks. I'm pretty much at the limitations of the computer's built-in sound system to be able to tell whether they handle cymbal transients well, but I expect that they actually would.
(Note here: cymbal transients are a good way to listen for distortion artifacts in your sound system. When you know what to listen for, you can diagnose a lot of different issues like high intermodulation distortion, harmonic distortion, phase and delay issues, speaker tuning issues, and the like. A good clean cymbal sound is a thing of joy, because it's rich in harmonics and sounds like a million crystal bells. A bad reproduction usually ends up sounding like a mishmash of hiss (intermodulation distortion) or a bunch of jagged broken glass being shoved in your ears (harmonic distortion)).
The response isn't flat. I can notice a hole somewhere in the mid-bass region-- not too deep, but noticeable when I'm looking for it. Not distracting unless you're critical listening.
Are they worth a hundred bucks?
Hmm... Id say seventy-five with no hesitation, maybe eighty. A hundred bucks seems steep to me for in-ear headphones, and I'm also a much bigger fan of the Sony MDR-7509HD studio monitoring headphones (over-the-ear model, list for $265). Then again, when I'm using headphones, it's usually in a professional capacity and I'm in it for the critical listening; if I'm just diggin' some tuneage and I can get by without needing ultra fidelity, these would probably keep me happy for quite a while.
I have to think that if you're doing a workout where sweat and movement may be a factor, these wee beasties may have a distinct advantage since they seem to have a decent "stickiness" to them with head movement without having that oh-god-what-is-in-my-ears feeling.