I noticed you mentioned the everSolo A6, and I wanted to share my opinion on it. I must say I was somewhat disappointed. While the app does flow better (compared to Volumio in my iFi ZS), likely due to the larger DDR memory of 4GB, as opposed to 1GB in the iFi, the sound quality with the digital out to my DAC wasn't noticeably better than the iFi. On the other hand, the analog out with the internal DAC wasn't particularly impressive, and I found it to be worse than the digital pairing.
I'm not sure if I received a defective unit, but for some reason, when I directly connect it to my PA in my second system, the speakers emit a hum. Interestingly, this doesn't happen with my main system. It's not a problem when I use the digital out to the DAC. Most of the glitches previously reported seem to be resolved with the latest firmware update. However, recently, the app has a glitch that plays the first track repeatedly, even when the setting is 'list played' and not 'repeated.'
I also had the chance to audition the Innuos Pulse Mini and Zen at a show and found that they performed better than the A6. It was in two different rooms with different system components, but that was the impression I got in that short time period. Anyway, just my two cents for what it's worth.