Waited a while to write this, wanted to give them some burn in time. Thoughts haven't changed though.
 
Just wanted to let people know this does not have the best clarity. Don't get me wrong, it's very good, and I think worth the money. The bass is HUGE (provided you get a good seal), with minimal sacrifice of other freqs; I get a little nauseous if I turn it up on something too bass heavy (and I love/need bass).
However, there is definitely noticeable lack of clarity in highs and mids. AKA: sounds a little muddy. Again, good sounds, and wide range--not cheap crap (I honestly dont understand people comparing these to crappy JVC HAFs and the likes).
I write this coming from the AT CKS-77x, which has more bass than you need as well, but has much better clarity in the highs and doesn't sacrifice bass. You can definitely FEEL the power of the larger drivers in the Sony and the amount of air it moves, but that's really about it. The CKS-77x definitely has crisper sounds, and without the sacrifice of bass. Check them out.
 
On the other hand, these are hands down the bassiest <100$ IEMs Ive tried. Large but comfy, moves lots of air, good range, could be clearer. Can't go wrong with them if you're looking for bass.

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 ...