Ok, if you already have a V2, and you're looking at $800-$1000+ A/D solutions why not step into a V3? I've heard the Mytek name, but I've never HEARD a Mytek, at least not that I'm aware of. Is there suppose to be some gain with going to the Mytek's A/D as opposed to the V3?
Mytek uses the CS5396 chip, what's in the V3?
I can't speak for anybody else, but personally, I don't particularly like the idea of an "all-in-one" box. I realize I'm in the vast minority here, but I'm just more comfortable with the idea that a device should do one thing, and do it well.
And before any of you start with the "But dude, your Mini-Me is an all-in-one LOL WTF!!!11!!" crap, let me just clarify by saying that I only run it line-in. And I know, I can't bypass the pre.
Anyway, my take: Ain't nothin' wrong with MMP > MME. Or, if you want to sell some gear and expirment a bit, there's a whole ton of possibilities. That's what great about dedicated boxes: there's so many ways to manipulate the sound. And, as far as pre-amp's go, no matter what new technology comes out, a great analog pre will always be just that.
I certainly enjoy my Grace > Apogee set-up, so there's a vote for that. As far as the question about Mytek, I've been seriously considering ditching the MME in favor of a Stereo192, because their A>D really does sound that damn good. Listen to the comps on their website for some studio stuff, or some of Chris Jones' recordings. True, a lot of that stuff is stack, but I believe there's some Red Rocks tapes out there. Even if you're not a DMB fan (for the record, I could go either way), they're nice just as a point of reference.
If it was me, I'd sell the UA5 and the Marantz, and throw the money towards another pre or a/d so you can A/B some different boxes and see what you like.