daveDerek pmed me last week asking for a little comparo between the portable headphones I own and he thought I should post my little write-up. Just my subjective impressions so take it with a grain of salt:
These are both very exceptional cans. I am actually on the fence still about the DT1350 but here's what I think in a nutshell:
ES10 - If Grado and Ultrasone had a baby the ES10s would be it. They're a slightly v-shaped, fun, unabashed party on your head. The decay on these is great but I found the tonality slightly unnatural. The bass depth and impact is a bass-lover's dream. Mids are clear but sound slightly distanced to my ears but I wouldn't call them very recessed at all. Highs are nice and crispy with no fatigue. Overall detail is great. A big caveat for me, is while I appreciate the sound, more than anything I need isolation for listening on the go. Not suitable for public transport IMO. Also the sound was slightly more aggressive than I prefer. Sometimes I want a more laidback sound.
DT1350 - Very neutral although I think it's on the slightly warm side of neutral. These are a totally different hp from the ES10s. Way more reserved, more balanced to my ears, and very transparent to source. There is a quick decay which I find a bit unnatural. The overall PRaT is pretty good however. Detail and separation is AMAZING. Really impressive. Soundstage is not that big but not narrower than the HD25. The ES10 sounds bigger as well but not a huge soundstage on those either since they have a very forward signature overall. The DTs are laidback in comparison. The bass has deep impact but no where near the ES10 or HD25 (which I actually miss and hope to repurchase a pair to compare side by side with the DT1350). Vocals sound very natural and the mids are probably the best part of this headphone. Highs are extended and very smooth.
Alright so not much of a nutshell haha. They're both great cans with different sound sigs. I would consider the K181 a more fun version of the DT1350 (they have a similar warmish tone to my ears) with bigger soundstage but lacking in the refined separation of the DT1350. The ES10 is the HD25 on steroids to my ears.
All in all, I miss the HD25, even though I have a love/hate relationship with them. To me, they seem to be a can that's in between the sig of the ES10 and DT1350. YMMV. I am very curious to try the Amperior though. I should also add that I am a big fan of the M-80. It's got a big, balanced, smooth sound for such a small can.