Yeah, fair enough, that was the first phone to spring to mind when you mentioned "tightness and articulation" as the bass on that phone also left an impression on me. (I wasn't as taken by its other qualities however, which include the sort of odd duck imaging, and the overall aloof nature of the mids) I'm actually quite intrigued that you feel that the bass exceeds that of the Ex1000 as that's another contender for all time best DD bass performance. I guess the only area of concern remains with the mids/treble (more aggressive upper mids than K3K, and advising to listen at lower volumes with comply). How much ear time are you able to get at a good listening volume before fatigue sets in? That was the one thing about the 1plus2 that totally did me in. The overall signature was so aggressive that I couldn't listen for more than an hour or so before I'd had enough, and on some songs, I had issues making it through without constantly fiddling with the volume.
My EX1000 is ancient, though, so perhaps age has not been kind to it, but at the point, I don't think the EX1000 can match the 2000J in bass articulation. Everything is on point, and I mean everything. It doesn't have that "way too fast to be realistic sound", either. Sub-bass carries the right amount of energy, and the mid-bass never ever gets away from itself. I have a bunch of tracks that I listen with to test mid-bass bloat, such as
La Venus du Melo from Stacey Kent. It is one of those tracks where the bass line will swing one of two ways: it will either bloat endlessly and muck up everything (think Westone W50), or be too tight for any kind of realistic presence (Etymotic ER4). Either way, that track's bass almost always sounds like a murky haze because the recording was mostly mixed that way. It takes an IEM (and amp) with stellar low frequency resolution to resolve the tiniest details in there. For example, the Custom Art Harmony 8/Pro (demo) does a great job of resolving the hidden bass texture in that track. The 2000J will do it too.
Something like Usher's
Foolin' Around is also great to hear for synthesized bass and an earphone's ability to render it. The track employs various different cut-off times for different bass beats, and a good earphone will be able to distinguish the smallest differences in note sustain and subsequent cut-off. Bass that is "too fast" can sound like it can't wait for the sustained notes to stop, while the loose bass earphones won't cut off the quick bass fast enough and leave lingering energy that will fog up the subsequent music. I will tend to try to standardize the "speed" of the bass response to a pair of very, very, very good loudspeakers.
In general, I err on the side of caution these days, and whenever I sense an earphone can be potentially fatiguing, I tend not to test my limits. Thus, I set the Concero HP to 2% on the Windows slider. For single track tests, I bump it up to 4%. Luckily, it's still pretty clear and resolving at 2%.
My reason for recommending Complys is that silicone tips tend to enhance the DN-2000J's tendency to resolve what I call, "treble detritus" --- basically sonic junk in the upper treble that grimes up music. They also make the decay of treble seem at times artificial, and Comply foams tend to make all that sound more natural. Even so, the timbre is a bit more natural sounding than, say, DUNU's own Titan 1, which can make piano strikes sound metallic. The 2000J doesn't seem to have this issue.
From memory, the 2000J doesn't strike me nearly as aggressive as is the 1Plus2, and it definitely doesn't share its odd faraway midrange presentation. A tamed down version (less bassy, less intensely spiky) of the XBA-A3 is a closer analogy.
