I do own both and it is a difficult question to answer with certainty as both are superb instruments...
On certain types of music, the Kaede presents a more lifelike and immersive listening experience, but as an all-arounder, the FX850 would probably be the better choice as it is somewhat more tolerant of less than perfect recordings and a variety of mid-fi sources. The Kaede is lighter in weight and is more comfortable for long listening sessions. I also notice more improvement in sound with the Kaede with my DX90 than I do with the 850 in comparison using my DX50.
I suppose I could liken this to discussing the differences between an Audi and BMW!
Edited by HiFlight - 4/25/14 at 7:51am