I'm running my A6A similarly: 2.1, Extra Bass on (to use the sub), front L/R set large. Enhancer off though. Mostly straight, or PureDirect for great recordings. Using the decoder in Auro3D for tracks that need ambience, and also for movies.
I really do like the crispness of the YPAO results. Logically it doesn't make sense to the purist in me, but I love the sound.