for less expensive the penon serial is fuller with much better bass but still crisp up top. for more expensive both the Andromeda and Solaris are great for me. used you can get either of those for about the same price as the ultra

This is exactly why limited editions work. They hooked you. It is unobtainium so it must be great. I have the og SA6 and it is very good. The ultra may offer some measure of improvement. Dunu I am sure will use the results of this collaboration to develop product in the future. All that said I have earphones I enjoy more that are on both sides of the cost spectrum. My point is don’t pine for a love affair that you cannot have. Find a love that is available to you.