Was finally able to pick up the KRK KNS8400 yesterday...the bad news is they're probably the worst sounding headphones I currently own...good news is the other contestants are a PS500 and an LCD-2 (only 2 other headphones I own atm), so that's really rather an unfair comparison :-P
- compared to the other two the bass is quite muddy and does bleed quite a bit into the mids, and they also sound a bit veiled overall.
- still plenty of detail and a very good overall balance
- I wore them pretty much the entire day today in the office and they're damn comfortable, also very light on the pressure, grado's are even lighter on the pressure, but the KRK pads are a lot more comfortable (I used to own a pair of Sennheiser HD-25-1 II and couldn't stand them for more than 15min as they felt like I had my head in a vice)
- sound isolation is brilliant, even on low volume (3-4 bars (out of 16) on a macbook air) I didn't even notice someone talking right behind me
- sound signature is very non-fatigueing to me and found it fairly easy to adjust to - as they'll be what I'll be using during the day and only switch to the high-enders at home in the evening the slight veiledness and muddy bass quickly become much less noticable (after the first 15-20min of listening in the morning I hardly noticed either anymore once my mind had adjusted to it). They do become a bit more obvious at higher sound levels but I prefer quite low levels for long term listening (i.e. the 3-4 bars mentioned above) and considering that the headhpones I'm comparing them against cost 3-5 times as much they're really doing pretty damn good
I'm really happy with them - they do exactly what I bought them for (long term comfort & sound isolation) as well as provide very good sound quality (for their price) :-)