If the S6 is so close to the Mojo as per Mimouille, it will be definitely the best dap in this price range. I got a short trial of the Mojo (~10 min) and to my expectations it's the best SQ I ever heard below $1000.
I don't need extra features too, and I believe that all bugs from the software can be corrected through FW updates. The best UI so far comes from Fiio and android based devices, but the best SQ always comes from devices that have a lot of flaws in terms of UI.
I was impressed with the S5 3rd annv, even with the flaws I really like the way it sounds. Not to mentioned that it has the best battery life I ever experienced from a dap.
I was going to order either a Shozy Alien or a Colorfly C10, but the S6 catched my curiosity and now I will definitely purchase it.