I've had a few days to make comparisons, so I thought I'd follow up on some briefs thought on the Yamaha YH-L700A and a comparison with the Drop Panda
Comfort and Build:
Clamp is stronger on the Pandas. The earpads feel nicer and better cushioned, but you still notice them on your head more than the more comfortable L700s. The headband on the L700 is definitely superior. The Pandas can develop a bit of a hotspot at the top, though I don't find them too bad unless it's a longer listening session. I don't love the material used for the headband on either headphone. The Panda has a rubberized material on the portion that touches your head and the L700s have fabric. Not a deal-breaker, and I guess they may not flake like pleater headbands are known to over time, but they feel a bit weird.
The plastic and overall construction on the L700 definitely feels better quality. There are known issue with the Panda handband failing, hard to say with the L700 since it hasn't been out long for people to throw around. I will warn that the L700s may not fit smaller heads. I only need two "clicks" on the earcups extensions to fit, and my head isn't small (on the Pandas I need six "clicks"), so if you have a really small head I could imagine them being too big.
Sound:
I should start by saying that I use the Pandas with SoundID personalization. I thought about doing the comparison with the default sound, but honestly the personalization improves the Pandas so much I wouldn't recommend them at all without it. So my listening with the Panda are with SoundID applied, my profile being "U-Type" according to the app:
Listening on both headphones done over Bluetooth with AptX Adaptive.
L700s have a more lively, exciting, consumer oriented sound. Even more U-shaped than my Panda SoundID profile I would say. Mids aren't necessarily recessed, but there's a lot of bass. It can be a little slow and boomy for my tastes in some songs. I've heard much worse in that regard, but the Panda is a little quicker and cleaner. The L700s have more impact for sure. I found upper mids and highs on the L700 detailed and natural most of the time, but they are a bit grainy and occasionally harsh. This is likely somewhat to do with imperfect recording and mastering in the music, but just keep in mind that these aren't a super-relaxed, easy listening headphone. They definitely put the upper end of the frequency response a bit forward, whereas even with soundID the Pandas are a little darker and roll off sooner. Timbre is a little more natural and smooth on the Pandas in my opinion, but not a huge difference. There's more of a sense of space with the L700s (3D off) compared to the Pandas, which present a more closed-in sound, but neither of these are "soundstage" monsters.
3D and head-tracking are interesting features, but not useful for music in my opinion. 3D is good good for movies, though I didn't find head-tracking to add anything to my experience.
Sample of test tracks:
Queens of the Stone Age - My God Is the Sun
Josh Ritter - Bright Smile
Purity Ring - Bodyache
The Flaming Lips - Race for the Prize (Mokran Mix)
Clipse - Lord Willin'
The Mountain Goats - Andrew Eldritch is Moving Back to Leeds
Solomon Burke - None of Us Are Free
Spoon - Finer Feelings
Freddie Hubbard - Gypsy Blue
Ariana Grande - Break Up with Your Girlfriend, I'm Bored
Conclusion:
Part of which headphone to get comes down to features. These are both bluetooth headphones, but the Yamaha has ANC, 3D and head-tracking features the Pandas obviously don't. The Pandas isolate well for a closed headphone, but if you're taking a lot of flights you would likely still miss ANC. On the other hand while both of these headphones sound good, the Pandas have an edge in my listening. The SoundID feature to personalize them is very useful and can really transforms the Drop Pandas. There are questions of durability and comfort that makes the Panda a riskier buy, especially if buying used without a warranty. I think the L700s are a bit too expensive. If they were $350 or even $400 they would be an easier buy, but $500 is a bit harder to justify in my head. The Panda retails at $400 when available, but can easily be found for 2nd hand $200 in good condition (which is how I got mine).