Okay, this will probably be one of my last posts on the v2, or whatever we're calling it (my vote: Mud). It's been a fun ride, but I've got reviews to work on and The Witcher 3 to play.
I called Adorama and told them the headband design was defective and that the product information didn't list the change from 2.5mm connectors to 3.5mm. They approved a full refund and provided a free return shipping. Great CS by the way, very fast and efficient. I was impressed.
I also took another listen comparing both 560's, this time on my big boy amp (LAu). Had the same conclusions that I had earlier comparing the two versions (which I'll refer to as "original" and "v2"):
The v2's clearly have less bass quantity, especially in the mid-bass and sub-bass compared to the originals. There's possibly even some slight roll off in the very low frequencies, although this could just be a perception from the reduced quantity. The mids on the v2's also feel like they've been emphasized more and are somewhat "meatier". There's something weird going on in the upper mids, I think they have a decent dip in them. No question the v2's aren't as bright sounding as the originals. Not only have the highs been reduced, they've also been rolled off some. Overall the treble come across slightly smoother sounding than the originals, but it's not nearly as crisp and energetic. I'd say overall the v2's is a more laid back sounding version of the original. To me this kind of takes away the best strengths of the original 560's and I personally enjoyed the originals more on almost everything I tested them on.
Finally
@givemetacos and some others wanted to know how the v2's compared to the Sundara's, so I gave them a quick comparison. My impressions: Buy the Sundara's.
Fine, I'll go into some details. The Sundara's are easier to drive, but the difference isn't that huge. I think they also don't scale quite as much with upstream gear, where the v2's (and originals) need to be pushed to be their best. The Sundara's have slightly more bass quantity than v2's, and the bass quality is no question better. The v2's do have a thicker midrange than the Sundara's, although like I mentioned above there's some wonkiness in the upper mids. I also feel like the v2's have a reduction or dip in the presence region. I forgot to mention this when comparing them to the originals, which are more closer aligned to the Sundara's in the treble. Also just like the originals, the Sundara's have better treble extension and quantity than the v2's. I think the quality is also better, but I'd need to spend some more time with them to be sure. The Sundara's also image better than the v2's, which is another area where I though the v2's weren't as good as the original 560's. Overall compared to the v2's, the Sundara's just feel like a much more complete sounding headphone from top to bottom. Now the Sundara's vs the original 560's, that's a lot closer ballgame. I could see preferences swinging either way depending on the user.
If there's one thing that this whole debacle has done for me is to appreciate how good the original 560's are. I had the original SMC version when I was still relatively new to the hobby and didn't have proper gear to pair it with. Ended up selling that pair, but I'm glad I decided to check them out again. I'll hold onto the v2's for another few days if anyone else has any questions.