Pros: Sound, Comfort, Design
Cons: Value, Price/Performance Ratio
Update: Reduced design rating due to ever-tangling cable. The cable is MADE with some type of built-in twisting/tangling design flaw. Just holding the headphones in my hand, the cable wants to twist and turn and due to its material, it's never fully "straightened out" like most other headphone cables. Due to this, it's become unusable.
I've owned the original Bose IEs and now bought these IE2s. In comparing the two, the IE2s have improved on the sound of the original. The originals were fairly dark and quiet. The addition of a couple of ports on the 'phones really helps the sound. These have better range by far. They're still, as with most Bose 'phones, emphasized on the bass and treble. The treble is slightly piercing but easy to get used to, and the emphasized bass isn't too boomy. Though you wouldn't use these for analytical or monitoring purposes, I don't mind the coloration, because I don't feel it detracts from the music.
The treble, mids, and upper-mid ranges are far better on the IE2s than on the IEs. All around, the sound has been improved. The bass is a little tighter. Acoustic guitars really come through beautifully in these 'phones. The mids are much less recessed than on the original IEs.
I think the hybrid in-ear/earbud unique design really helps the comfort of these. These are some of the most transparent headphones I've tried. I forgot that they are there, and they are extremely comfortable. After hours and hours of listening, there is no discomfort. I never had a problem with the tips staying in my ears, even on the originals, but they've included new tips with a new design along with the standard tips, to help them stay in the ears, since users did report that problem originally.
Despite the understandable common dislike for Bose due to the coloration of sound and overall high price, I think from a completely unbiased ear, they don't sound bad at all. Bose has been very well-known to have great customer service, and I think that's actually what I'm paying for when I pay more for the headphones. They've been known to replace headphones slightly out of warranty or go to great lengths for customers with any issues. That's worth a premium, IMO.
I prefer earbud-style 'phones to those that go into the ear canal, so these right now are my in-ear 'phones of choice. Especially if you get these on sale, I don't think you'll regret the purchase. At $100.00 they're slightly over-priced, but you get good customer service as a bonus, and that may make up for it.
On a final note, in regards to isolation, these are NOT intended to isolate barely at all. With music at a medium volume level, they do a decent job, but do not expect these to have any isolation value in comparison to canalphones. They provide maybe a slight bit more than your standard earbuds from Apple or your higher-end ones from Yuin.