Best closed back circumaural 'phones for under £150
I've used a pair of Sennheiser HD595 at home for about eighteen months now and love them to pieces for both music and gaming. When my taste in music veers into darker areas though (Isis, Neurosis, Pelican, Meshuggah...) I find that rather than sounding downright apocalyptic things start to feel a little bit frustrated. I'm looking for a pair of closed back headphones with a little more power at the low end to supplement my current pair of Senns.
I've been considering Shure SR840 but they're right at the edge of my price range and I've heard they can sound muddy un-amped. Audio Technica ATH-A500 and ATH-M50 seem popular, as do Ultrasone HFI-780, but from the look of them I'm not convinced about their long-term comfort. Buying a dedicated headphone amp is a possibility but that adds another £100+ into the mix so I'd rather not unless it's really going to be worth it.
Anybody any suggestions?