I have all three versions of the EX-29. Each uses different drivers.
V1 has a lot of bass and is tame up top, which eqing with a single bass/treble mass eq knob works great on. Surprisingly decent sound when you do that. It had the largest earcup, the tightest seal, and the most isolation.
V2 has slightly less bass than neutral, but very clear, expressive mids. Smaller earcup, thinner earpad that are a bit hard. Pretty tight sound.
V3 current version has the most neutral sound of all three, but is a little soft and flabby in transients. Not as tight as V2. I would say it's the smoothest and most euphonic of them. Same earcup as V2, softer earpad. Seals about the same as V2. I've got two of these.
V1 has the driver bare-mounted in the aviation/shooting headset. V2 & V3 have their drivers in separate housings. V3 has a MUCH better plug with screw-on 1/4 inch.
I had a pair of HN-7506 before these. I found the bass weird, the mids very glassy, and the highs at least not as coarse and bright as the Sony. The earpads also kept rupturing. Supposedly memory foam or oil-filled earpads are more durable than the gell things. They isolated as well as the ER4S, which is as good as it gets.
Though you could argue the HN does some things better than the Direct Sound EX-29s and definitely sounds closer to the Sony, I found the EX-29's had a higher resolution and were less fatiguing for some reason...in spite of their other sonic issues. They're also lighter. The HN sounds perhaps more "hifi".