First off, I got the 9963's, because there were lots of comments about how it's the better deal.
Got these because of all the head-fi rave, but they sound mediocre to me at best. Honestly, I'm not audiophile, and my hearing has been getting noticeably worse as of late, but these sound no different from my beat up MDR-J10s. Could be just me, but I was really disappointed after all the hype. I felt NO punch from the bass, and the build quality is no different than those mdrs. The driver enclosure is big on me (and I have pretty average size ears), hurts because of the stupid sharp ridges on the outside (I'd file it down, if I cared more about it. I nearly tossed it though), and the cable really feels cheap.
I used the J10s for a longass time with no complaint and these sound really no better to me, but I guess I was just in search of something stronger. This wasn't it for me. I need to feel my bass, not this squeaky crap that hurts my ears.
Went ahead and dropped 6x the money for a proper IEM ...