The graphs are flawed - but they usually vary less than human opinions.
Look up any headphone on head-fi and read 20 threads about it and you will come out knowing it is:
"A bass-shy anemic basshead can with recessed brilliant forward mid range that lacks detail and exposes poor bitrates with rolled off bright creamy airy highs that cause tinnitus + needs an amp (no particular reason or specific amp mentioned)".
Your best bet is looking at 2-3 charts from different sources and averaging them out then read reviews by people who have *actually owned them*, then you have a pretty solid idea of what to expect, I'd say.
Edited by machoboy - 11/18/12 at 9:10pm