It's interesting that the OP found the Okto dac8 Stereo to be characterized by " 'wall of sound' and very in-your-face without soundstage nuance, seemed accurate and detailed with huge bottom end but was harsh/unforgiving on top." The list of auditioned DACs is amazing and I've certainly never heard most of them, but I find the Okto to be very different in concert with my admittedly new Modwright KWH 225i.
Compared with the mid-level DACs I own (the Chord Qutest, the miniDSP SHD and the NAD M32's internal DAC), I find the Okto's soundstage to extend beyond the speakers laterally when appropriate, while - for example - constraining a solo piano or small jazz combo to where they should be. Perhaps most impressively for me, I've experienced surprising front/back soundstage depth. I also haven't experienced top-end glare or harshness, although I recognize that speakers, cables, and room play important roles here.
I don't claim that the Okto dac8 Stereo is superior to the extraordinary DACs on the OP's list, but I'm very pleased with it in my system thus far.