I have HD449. They sound good but there is a problem: cups somehow press ears so I feel pain and get tired of them too fast.
Tried HD598, but they sound too bright. Now I try NAD Viso HP50. The 1st impression was quite good, headphones are very light, but the problem of pain returned back. It looks that I need over ear headphones. There is also lack of bass comparing to HD449. I could say that bass in 449 is more powerful. Overall sound of NAD is a bit unpleasantly piercing and strident to me. Probably this is because turn volume up too high seeking for bass...
So, what do you recommend me to search for? Usually I listen to such bands like Marilyn Manson, Prodigy, Rammstein, Nirvana, some little known rock bands and piano or organ based classic, but not that much. All in all I value good bass and volumetric sound combined with ear comfort. Probably it should be something like HD449 with bigger cups.
And one more question about amplifier. I bought Arcam rPac and experience the problem described here:http://www.whathifi.com/forum/dacs/arcam-rpac-troubles , so I hope to change it to something else. Which portable amplifier you would recommend to? Salesman suggested some small cylindrical-looking amplifier (I didn't remember the name, but it's something quite famous), but I am not sure... Probably it is better to invest into headphones, not amp.