Yeah I'd think he'd have to consider stuff like the Angies, Noble 4S,1964-V6, 1Plus2, Parterre, and possibly going custom at that price range right with something like the Unique Melody Miracle.
Although I'd be really curios how much better they are than lower priced flagships like the Dunu 2000J, Fidue A83, and Ortofon E-Q8.
I honestly think the Angie smacks down every single one of those phones you listed and I've heard them all save for the Miracle and the V6.
EQ-8 is my absolute favorite at that price range, and is exceptionally good for the money, very nice neutralish sig that's probably 90% of the Angie for quite a bit less money. I'd imagine it's easier on the ears than the D2KJ, if Tomscy and James' impressions are anything to go by. Midrange would be richer/more upfront than the 2KJ based on K3003 comparisons by Tom/James. Only issue is that it's kind of a tough phone to drive, being very sensitive and requiring as close to 1 Ohm OI as you can get. (It sounds fine out of my iPhone 6 but is smoother and weightier in the low end with the Leckerton) Doubt the Fidue holds up if Tom's recessed upper midrange observation is correct (and it should be, he has good ears). He felt the mids on the Fidue were congested/veiled.
Anywho, I just came back from listening to the UM Mason, UM Maverick and HE1000. I felt the Maverick had great bass, with very good extension, body and tactility (perhaps owing to a very unusual dynamic driver X BA design for the lows), but I was let down by the treble which, while very clear, came through with excessive emphasis. Running tone gen revealed some peaks at 8, 10 and 12 khz. So uh... yeah, it was kinda annoying to listen to with poorly mixed music. Listening to something like Relationship of Command was just plain irritating to me, while it's much more manageable on the Angie. Soundstage had that typical concentric feeling stage that stage monitors have (decent width, but good height). At $1,000 I wasn't particularly impressed as it felt too run of the mill I guess.
The 12 driver Mason immediately felt much smoother across the FR than the Maverick, and possessed greater width to the stage. Clarity was excellent but it felt too smooth and laidback for my tastes. This was immediately noticeable when I queued up Dark Defender from the Evangelion 3.0 OST:
https://www.youtube.com/watch?v=uWqY6DM_qFs
The brass section just lacked the explosive dynamics that the Angie possessed, sounding too even in volume to the point of feeling sort of lifeless. The Angie managed superior layering, and sounded audibly more lively across the board making the Mason feel almost strangely veiled, in spite of all of the minute details actually being retained across both phones. It almost felt as if the upper end of the Mason was shelved or something. Very odd. I'm not sure if it was on account of a poor source matching, but seeing how I used the Leckerton UHA-6S MK II I kinda doubt it. I'll probably have to get around to listening to the Mason again next time I meet up since I spent most of my time listening to the HE1000.
Speaking of the HE1000, christ what a huge ass phone.
I had to actually stack a wad of paper towels on top of my head cause the lowest setting on the sliders still wasn't a comfy fit for me! It looked much nicer in person and felt very, very solid. I loved the swivel joints, very smooth action.
I had a friend queue up Google Play and was very impressed by the HE1000 through the Asus Essence 3 DAC/Amp. It moved a huge amount of air (the HE560 didn't compare in that regard), and felt pretty crystalline in detail. I was most impressed by how it matched something like the Angie in terms of black space/imaging. I've always felt like multi BA IEMs felt more precise in terms of placement, separation and "air" around instruments, but this really did feel like you could have your cake and eat it too. Long story short, I did feel like it managed to couple that gut churning planar punch with the texture of an electrostatic presentation. I don't think I'd pay $3,000 for it, but it was a very impressive phone.
Oh yeah, the Oppo PM3 was there as well. Switching from either the HE1000/HE560 to the PM3 was pretty hilarious. Felt like the walls were closing in, and everything became super honky, which is pretty funny cause I thought the PM3 sounded pretty darn nice all on its own. I guess that's what laid-back treble/upper mids will do to you.