I actually agree that if you prefer "colored" (coloured to you Brits and Canadians) sound to "accurate", then you should probably buy the Grados. I mean, no headphones are perfect, so if these posess the imperfections you find not only easiest to live with, but actually appealing, GO FOR IT!
I, on the other hand, WILL NEVER deliberately choose non-flat headphones/speakers for listening to music. I'm NOT a "purist" when it comes to PRODUCING RECORDINGS! God knows that in my own radio production I pour on liberal amounts of equalization, limiting, compression, digital reverb, phasing, flanging, and any other damn thing that will make the sound coming out of the speakers/headphones match the sound I HEAR IN MY HEAD! That's all a part of the creative process. But I think the "creative process" ends in the studio. When I LISTEN to completed work (and I certainly consider my work to be a completed product! I don't want ANYBODY f##king with it by changing the eq to "enhance" it, etc!) I want to hear WHAT'S ON THE RECORDING! For that, FOR ME only "flat" headphones/speakers (with LINEAR frequency response) will do. So I choose Sennheiser HD-580s, or HD-600s (BeyerDynamic DT-990 pros, DT-150s, etc...you get what I'm talking about) rather than Grados (or even my beloved MONITORING/TRACKING/MIXING headphones the Sony MDR-V6/7506).
I draw this analogy to home theater. If you are one of those guys who likes the color saturation turned WAY too high because you "like the purdy colors", then it's your damn home...watch it the way you like it. But if you're a "real" film buff, you want to see WHAT THE FILM PRINT LOOKED LIKE! For that, you need your tv/video projector properly calibrated for neutrality! When I listen to a recording made by a TEAM whose work I trust (artist/producer/engineer), I want to hear WHAT THEY RECORDED! I want my HD-580 (or one of the other models mentioned). And when the recording ISN'T reference quality, I'm not above using equalization TO CORRECT bad eq/bad mastering/mixing by a DEAF engineer! If you start with a neutral sounding headphone like the models I've mentioned, it's much easier to equalize bad recordings to sound the way you think they should, than if the headphones/speakers are already imposing their own "editorial opinion".
I DO NOT think the purpose is to get "closer to the music". I think the distance we seem to be from the music is a part of the creative process determined by the creative team at the time of recording/mixing/mastering! Take it from a trumpet player. Getting "closer to the music" isn't necessarily a good thing, and can actually be quite bad. INSIDE THE ORCHESTRA playing an instrument is about as close as you can get. And it's the lousiest place in the entire hall to HEAR THE MUSIC! What you hear is VERY distorted, because you're TOO DAMN CLOSE! Acoustic music DEMANDS acoustic "space". You're not supposed to hear the "individual strands of music". It's not about INDIVIDUAL STRANDS! It's about a homogenized whole! And this homogenization largely occurs as the sounds from various instruments in the ensemble blend together in the atmosphere...the acoustic space between the audience and the performers. A device which arbitrarily pulls you MUCH CLOSER certainly isn't serving the music, IN MY OPINION!
Everyone is familiar with the term "can't see the forest for the trees". I'm afraid too many audiophiles can't hear the music for the "strands". They're too damn busy trying to dissect a recording into it's individual sonic parts that they don't realize that it's SUPPOSED TO ALL BLEND TOGETHER! Being able to hear each individual element often is exactly the opposite of what the musicians intended! Tired of my acoustic/classical analogies? Fine...I submit to you as evidence of the above PHIL SPECTOR! Perhaps the greatest rock and roll producer ever would be SHOCKED and dismayed that anyone was attempting to hear "each individual instrument". "Man you just don't get it", he'd probably say...or something similar.
You have no idea how much time I spend in producing what I hope will be a "photo realistic" radio commercial taking sound effects from many different sources, and processing them so that they BLEND together, and seem to all happen in the same acoustic space. I certainly don't want the listener to be able to tell that the bird in the left speaker and the dog barking in the right were recorded at different times, in different places. If I do my job, it all blends together seamlessly. You don't notice the "individual strands". They all fit together to form a WHOLE image. And THAT is the point of MIXING!
WHEW! Now the Reader's Digest version. It's your money. Spend it as you'd like. If you want to get infinitely "closer to the music", go ahead. But I would point out that getting "infinitely closer to the music" IS NOT about the search for greater sonic TRUTH. OFTEN those who created the recording INTENDED for you to listen at a distance! Moving in closer in spite of their wishes ISN'T "high fidelity"