bad for listening because most of them have harsh highs. easy to get ear fatigue
worst for mixing, do not mix with these headphones because they have the V eq pattern voicing. exaggerated bass, no mids, a lot of highs
good only during tracking and practicing with your buddies thru jamhub
which is my primary purpose, they are cheap though so i bought several already:
hd681 - the first one i bought, very midscooped sounding. ang laki ng sound stage. cant be compared against my akg k240, ang layo ng tunog. manipis ang 681
661 - much better than 681 as there are more frequencies available
668 - the best of the lot but still midscooped
i've also tried the below 1500-peso variety and my advice is stay away from them - ngo ngo ang mids. im still interested with hd681F (if i ever find somebody who sells it) just for kicks to listen if it really does sound flat as they claim it to be.
to add, i also have the hd381 in-ears - great sound for a really low price. this is my daily beater when commuting. hassle lang yung construction kasi akward yung position nung rubber tip.