i got the dt 770s, which were a really old import. the headband was warped, and the flimsy plastic bits at the end of the yokes didn't inspire much confidence, so i returned them.
then i got the hd 490 pros. i have a massive head, so for the first couple of days, the clamp force was a bit much. however, they are an excellent pair. now, they don't sound as impressive as i'd hoped, probably because i don't have a dedicated dac/amp, i wouldn't know. plus, they lack soundstage. but they are an excellent platform, or so they say, and i think i understand why. every choice about their design has been very thoughtfully made; nothing about it will have you complaining down the line. so long as you stay reasonable, of course.
some might mistake the plastic for poor build quality, but it's not. in fact, it's really good plastic, well built, and very light – "glass fibre-impregnated pa6 nylon," as described by cammyfi. i'm a sucker for good plastic.
now, i'm returning this pair as well, but for unrelated reasons. what i'm looking for is something with a wider soundstage and better comfort. had i kept these on for a couple weeks more, they'd have gotten as comfortable as everyone touts them to be. or so i've been told.
erm. open to suggestions. i think i found the beyers more comfortable out of the box, but that was a weird unit. i have no confidence in how well or poorly they're built. well, that's false, i have some confidence. i'm fairly confident that their construction will fail on me exactly as described by saurav.
if i don't find anything i'll probably get the 490s again; they're not particularly impressive, but that doesn't mean they're particularly bad either. please do not conflate as such.