I am glad you are liking them. I just got mine in the other day and really like them too. I don't find the lyrics hard to understand but everyone hears a little differently. Do yourself a favor and stay away from 5 Finger Death Punch with these headphones, I am not a fan myself but a good friend of mine is and to me it is the only band with a real problem with the sounds. I forgtet the word but words ending in S and F sounds are unbearable but I haven't found this to be the case with any other vocalist.
Enjoy the cans, one Amperior Lover to another.
Yeah the headphones are slightly siblant and also Ivan moody isn't the best singer so he probably doesn't know how to sing and make s and fs sound a little more bearable. It could also be a mixing problem. A7x has this same problem but I find it even worse with them.