I think the K701s have decent cost/performance ratio
I feel the construction is superb(would like it to have detachable cables, but that's my only gripe)
They certainly look more expensive than my K1000s
While we don't know how long they last but they're downright cheap! A headphone this good for this price?!?!
They don't need nearly enough power as my K1000s, sound great out of soundcard/ipod/ppa/anything I throw at it
I think for the average listener, these babies beg for either 1.amp with variable bass or 2.EQ
I'm definitely going to start using these portably.
Make sure you consider these points:
1. Comfort, I feel they definitely outclass the HD650 in comfort(subjective here obviously).
2. Looks(could be a con, depends on taste... subjective again)
3. Price was a really strong point, don't know what kind of prices they are at now
4. If you like more bass'ier things, make sure you have variable bass or EQ(or go with something like the HD650, DT 770/80)
5. I wouldn't say they absolutely need a dedicated amp. They sound decent straight out the iPod. I know many people have said these things are power hungry but I'm finding otherwise. Although since K1000s are my "reference cans" I guess you could contribute that to my point of reference
6. Technically capable cans, that they are... the sound just isn't for(I'm speculating) most people.
EDIT: 7. There was a mention of their plastic'like feel. Yes, they definitely do feel like overgrown ibuds. I would agree that they feel cheaper than they look... by a long shot. The brown leather headband is the only thing that feels semi-expensive.
I know I said both:
1. construction is superb
2. they feel cheaper than they look
It's true they feel cheap, but I think the construction is very good(sounds like a contridiction, I know). Most of the design seems very well thought out. They look gorgeous to me and they're very comfortable.
I had similar feelings about the K1000s: They felt really cheap, but the contruction was very good