Cons: Little too much bass & treble, expensive now
I really like these IEMs. The casing is almost indestructible, they have detachable cables, and the sound is great and very clear for dynamic drivers.
The casing is made from Zirconium. They're advertised as being related to diamond, which isn't true and a little too much marketing speak, they are indeed very very hard.
The sound is a little bit V-shaped with too much emphasis on the bass & treble. It can be fixed through the use of an equalizer, but it'd be nice if it were more neutral out of the box. But the clarity is fantastic, the bass extension great, the treble very lively.
The cable is very high quality. My only qualm is that it is a bit on the short side. If I use these with my iPhone in my pocket the cable barely reaches and will tug if I turn my head while wearing them over the ears. It really could be about 6" longer, but you can fix this easily through the use of something like the iLuv EA15, an iPod/iPhone remote that adds 7". Or you can just replace the cables with Sleek Audio SA6 replacement cable, the port is the same.
Durability anecdote: My Corgi likes to eat my IEMs and he got a hold of these once. The earbud came unattached from the cable, he chewed on and he swallowed it. I made him throw up with some hydrogen peroxide per my Vet's advice. 5 minutes later out the missing earbud came, covered in foam but absolutely scratch free. I cleaned it up in some rubbing alcohol, let it dry out and put a new tip on it. Much to my surprise it worked fine! The screen mesh on the nozzle kept all moisture out and the driver was undamaged. Can't say that about any other IEM - surviving 30 minutes inside a dog's stomach.