Well been trying the 2002 and 2000J's together.
First of all build. The 2000J's are clearly sleeker and sexier while the 20002's are more unwieldy, however they fit my ears fine both over ear and straight down. But I can see how the 2002's wouldn't be for everyone's comfort. In my case that is not an issue. The 2000J's have a nice build quality but the cable is quite thin and once you have the 20002's in your hand - well they are built like a tank and feel like one as well. They just give you more confidence IMO. The barrel for the cable connection is actually quite useful to use as a grabbing point to jam them in your ears with - so if the fit of the 20002's is fine with you, they are probably easier to insert over ear as the 2000J's, who only have a small housing to grab onto to jam them into your ears with.
As far as sound I did hours of A/B testing on these. Mostly with electronic music, some pop and rock.
This is WITH the bass rings on the 2000J's the entire time. Complys on both pairs. Bass slam is virtually identical. I couldn't pick one or the other. Overall sound signature is where things change a bit. Overall the 20002 is meatier and fuller whereas the 2000J is thinner and airier. While the bass slam is the same on both, the 2002 just has a little more roundness to the sound vs the 2000J. It works better for some tracks and not as good for others really, and the difference is not that big but it's there for sure. That's the best way I can describe it. HifiChris puts it into better words in his review
http://www.head-fi.org/products/dunu-dn-2002/reviews/16013
Overall I can't decide which to keep. Right now my pair of 2002's cuts in and out only when used with my phone which no other headset I have does. So those are going back. I'll order another pair of 2002's and see if they exhibit the same behavior or not and then make a final decision. now to test them against the FLC8S to decide if those are being sold or not.