Just Received my Zero One Mercury Today

How much does the Zero One Mercury cost?

Answer to my own question: I went to the Zero One website and checked the prices. Seems reasonable. This is one unit I will seriously consider.

If it is as good as advertised, I would replace my one-box player for it.

Some further Observations:

No dither still sounds best to me. I don't really hear any difference with the Nyquist and Nshape dither options, except maybe a bit more low-level noise. The TPDF dither initially sounded good, as it seemed to enhance the upper frequency ranges, but it soon grew annoying, especially with solo piano, as it began to sound "clangy". In doing some reading up on dither and its uses, I found references that state that, for audio, use of dither is definitely superior to simple truncation (i.e. no dithering) to 8 and 12 bits, has a smaller effect on 16 bit data, but makes an inaudible difference on 24 bit data. As the internal DAC in the Mercury is 24 bit (assuming it uses the same chips as the Ar38 DAC), there should really be no need for dithering at all, as quantization error is inaudible with a 24 bit word length. That is confirmed by what I hear.
I have settled on the HQ1 filter for now, as is has a much gentler slope than the Redbook brickwall, but still filters out the ultrasonic hash that might play havoc with the rest of my system.
Still loving the 24 bit word length and 192 KHz upsampling frequency.
Ripped 30 CDs last night, about 1/10 of the way there...