I also thought the exaSound e28 was promising. So much so I went ahead and purchased an e22 (top of the line, 2-channel). Unfortunately it underwhelmed me sound-wise.
Playing PCM through JRiver, be it 16/44 or 24/192, it did not outperform my Audiophilleo plus Metrum Octave, which are 2 years old and for a combined price of 60% of the e22. When upconverting PCM to DSD with JRiver and into the e22, it didn't sound better than the incumbent setup either, with WS2012 and AudioOptimizer.
It did have a slight edge with HQPlayer used to upconvert. It worked well, but alas, HQPlayer doesn't work with AudiophileOptimizer...and the user interface seems designed for someone sitting on a computer...not for my needs with a headless setup. And upconverting, even in 2-channel, is resource intensive. 8-channels wouldn't be possible. Neither can Acourate work on DSD for that matter.
So exaSound is not a good option for me.
From further reading I kind of concluded the best option, although expensive, is the Prism Titan, followed by the Lynx Hilo. I think I will give the Hilo a shot. I'm having a hard time digesting the idea of letting go of my preamp, though. I guess getting into Acourate room correction and digital crossovers with a Hilo will be my big endeavor for 2015 :-)