I got my replacement Nano in a few days ago. I already sold the XS. There’s a definite difference in speed, detail and clarity, which to me also helps with imaging. Treble is maybe a bit brighter and more airy, but I prefer this and don’t find it too bright at all. Timbre is about the same to me. I also think the Nano is a better complement to my only other set of headphones, I actually use, the OG Clear.
I’d say it’s close but noticeable and easily worth the $100-150, on sound alone. I actually wonder if the more difficult question is whether the Arya SE is worth 400 more than the Ananda now that the Arya SE is 1000 new. Without ever hearing the Arya I’d guess not, but would be interested in hearing what others thought.
The biggest difference is probably fit and comfort, which will probably be very person specific. The Edition XS is much looser on the head, and for me I actually felt the band less than the suspension band on the Ananda. So if you have a big round head, the Edition XS will probably be much more comfortable, especially since both cups are huge but the Ananda puts more stress on the jaw area because of the clamp and lack of swivel. The Ananda fit much better for me. The XS was super comfy on the head but a bit too loose for me to the point that I couldn’t really move my head without them slipping, and/or making a creaking sound. Also harder to make a good seal for the same reason.