The 8400s look pretty nice and he makes them seem pretty stellar - worth $250 at least in his eyes. Will pay more attention to those, plus they have memory foam ear cups and at only $80 that's some ridiculous value.
How do they compare to the 770 in your opinion? Looked around here and people tend to prefer the beyers.
Better bass on 770s...better mids/treble on 8400 to my ears.