Monte is an upstanding, long time member on HF.  He sold his HD800, Arete/Volcano, and now his Neko at great prices on a whim.  I wouldn't hesitate buying from him for a second.

The exasound looks really interesting.  Can't comment as I've never heard it and have no idea who runs it.  Suffice to say that "Async, 9018, galvanic isolation, DSD" are great selling points but don't tell you everything about the DAC's implementation.  The Invicta uses an original algorithm for dithering that no one else incorporates.  It is designed by Dustin Forman, who was the engineer behind the 9018 and has quite a few patents to his name.  The SDXC card (with HDMI out for control on a screen) was a big plus for me, as is the OLED display, the build quality, and the 30 day guaranty.  The headphone out on the unit is also pretty great.  Also includes a remote, which is a feature that adds more to cost than you would think, especially on small-run units.  The Invicta will have DSD capabilities within the year but I don't have any idea whether they plan on supporting 384.  If you read what Lavry has to say on the matter there's a significant downside to 192 and 384 anyways and there is not much out there recorded in DSD.

Looks like both these DACs have a 30 day risk-free trial, so there's nothing to stop you from trying out the cheaper e20 first and then returning if you don't like it and going for the Invicta.

Ideally less than $2k, but in reality I could go higher - it just becomes an issue of "is this worth it?" more than "can I afford it?"  I think the former comes into play far before the latter.

I kinda have a friendly disagreement with most of the other pirates here on this issue.  I think that, practically at least, DACs are least important part of the system since even cheap ones are so damn good in the big picture of overall SQ.  I haven't been convinced that a lot of the differences people talk about between DACs are actually real either.

Anyway, I'm not here to tell you what you should or shouldn't believe, just to present the counter point and let you make up your mind.

You're talking about spending a lot of money and I think you'd probably get a bigger improvement for it if you spent it somewhere else.  A new set of 'phones if there's a pair you've had you eye on or maybe a dedicated 'stat amp for the 404LE.  I've heard good things about the S7 so that's probably a keeper.

OTOH, if you're in love with the rest of your system then a DAC really is the only place to go.

Also, if you decide to go for the PWD MK2 I can direct you to a dealer who sells them for $2700 brand spanking new.

As for the whole placebo thing/"All DACs go to heaven", that's why I ordered the Cantata.  At least if it's all in my head I have something pretty to look at.

NAD m51, because Australia gets NADs cheap.