Regarding ess DAC's: and the implementation:
The exasound I mentioned is a wonderful DSD player- DSD on this unit "seems" to sound as good with DSD as DSD through my Weiss 501, I think that is because the exasound's engineer Klissarov made DSD a strength, whereas Weiss focused on upsampling. I am not saying the exasound is a better player, but playing DSD files definitely sound better on the exasound vs. other formats, whereas a DSD file on the Weiss don't jump out as a level up, but just sound no better than redbook. Yes, the Weiss digs deeper into the recordings regardless of format. So now I am rethinking "DSD is king" that I thought before with my previous DAC. I see you currently have the same priority I had.
Interestingly, and my point: they both have the same Sabre 9018 chips. While their sonic signatures and soundstages are similar, the implementation of the DAC is the key. Daniel Weiss has all the knowledge and tools to utilize whatever strategies he feels is best, and yet he chose ESS chipsets over other options. There is a much more extensive (and thus expensive) DAC build in the Weiss than George did with the exasound- built in streamer and power supply in the 501 vs. wall wort for the most obvious examples, and many other topologies that are beyond my knowledge level, but there is alot of this "ess vs. r2r/fpga dac's" going around the forums, and others have mentioned perhaps that is not the right first question to ask.
