For anyone reading this thread ... to make more sense of it and not give false info that I have a lot here...
I was used more to the darker sound and thus HD380 appealed to me. I was also used to lots of sub as my home theater has a lot of it. So ... when I compared HD598, Grados, HD380 etc, etc the ones that had the most bass clearly stood out. This is not the right way of picking a headphone.
I can now say that .... after testing
You get used to the sound you listen to. Once something is different, we tend to possibly dislike or feel like it's bad. Get you ears to adjust first
I liked HD380 but now I hear that others like HD598, Grados, Momentum, Shure are much more detailed. They are also all brighter than HD380 which I now like. Now the HD380 to me sounds like a nice product but I am starting to like a different kind of sound.
It really depends on the music. Once song will sound best in HD598 and the other one is best on Grados (this happened to me). I think that there is no such thing as the best headphone. It really depends on your music you listen to and how you want to hear it.
Once you think about buying something "professional" grade .. it almost always requires an extra piece of equipment. Good example .... HD600 is a shame to listen to without an amp. For me, because I don't want to buy an amp, I found that HD598 is a better solution.
Comfort .... I didn't think that this is so important. It's crucial. I noticed that after 30 minutes I wanted to tear HD380 off of my head as it was just giving me a headache. HD598 is awesome. Grados are great for some songs but their fit is just weird. Momentum are great ... like I said before ... awesome for portable and again ... some songs it;'s good with and some it's really, really bad.
Pick 10 songs you listen to. The kind of music you will most likely listen to and run it on all headphones you consider. I can guarantee that no one headphone will beat other on all 10 songs. Just pick the one that had a majority. For me ... it seems like it's going to be HD598. by the way .... when I added a bit of bass in my Winamp EQ, I wasn't too crazy with the outcome.
I really want to compare the Beyerdynamics DT880, 990, etc but all of them require an amp and I don't feel like going too PRO with the whole headphones music arena.