Yes, graphs can be useful but only to limited extent and will not replace proper audition tests.
More so, Music, you perhaps do not know how much audio pro people laugh and ridicule us, audiophiles. In particular many pros laugh us loud for our refusal to use EQ for tweaking sound to neutral, they say we are overpaying for gear and matching equipment only to achieve what can be achieved with EQ without spending fortune. Problem is in older days i had Fisher Studio Standard system with 14 level per channel EQ plus one parametric EQ, today such things exist mostly for pro systems only or in computer audio.
Still i am corny and prefer to live without EQ :-)
Edited by Gintaras - 8/18/13 at 1:38pm