Have been enjoying my new snapdragon Note 4 and since my wife just got an S6, thought I would compare rmaa data.  This was not done with professional level gear but was done with the exact same equipment(using voodoo audio test with all effects off).  There has been a lot of hype on the wolfson Dac in the S6 but without people like François Simond(supercurio) and the WISCE data(wolfson chip tuning software) the true potential may never be reached.  On the other hand there has been a general lack of respect for snapdragon Dacs.  When I did some listening at a local store, I couldn't hear much difference.  So I got a Note 4, in view of screen size, battery, sd card.  As the testing shows, there is really no major difference in sound specs.  I tested at 2 power outputs since I did notice my Note 2 had some issues using stock drivers at lower power.  One other point not shown, I needed 14/15 to reach -1 db with the S6 but got this with maybe 10/15 with the Note.  I was using faux sound on the snapdragon which does boost the power if needed.
 
Bottom line: snapdragon certainly is competitive with the wolfson dac
 

I posted my opinions on my listening test in the S6 thread (Klipsch X10i & Shure SE846) and I find them very similar but do prefer the Note 4 Snapdragon better. I am keeping the Note 4 over the S6 for a number of reasons.

That's stock, the reason why people loved the wolfson dac on smartphones is apps like voodoo that skips the samsung/android sound api for much better sound quality. The stock samsung api is not really good. The specs shown above is just a small part of the story, e.g. how's the bass impact, instrument decay, etc given those numbers? How is the distortion when i connect my 9ohm iems, what about 80 ohm headphones?