I'm with Varti, I'm afraid. In my experience of using palmtops (almost three decades: various Psions, including a 5mx that I used until getting a Gemini, and now an Astro), all other things being equal, a machine which is with you is always better than one which isn't. (That's why so many photos are taken with phones these days, even by people who own much better cameras: phones are there when needed.)
An Astro fits into a trouser pocket. (I'd prefer a bit thinner and lighter, of course, but for me it's a reasonable compromise; the 5mx was bigger still.) And so it's always with me: at home, at work, on the train, visiting family and friends, wherever. That means it gets used.
A device the size of this MNT simply isn't carryable in the same way. That would make it far less useful for many of the things I'd want it for. I don't need a powerful mini-laptop at home; I already have a far better desktop machine. And what would be the point of a device for taking notes or looking up info, which isn't there at the point you suddenly find you have notes to take or info to look up?
Yes, upgradeability and use of standard components is great; but in this case the cost is heavy in terms of size and weight — much too heavy for me.
However, I'm sure it'll work for some people, and I wish them all the best for it!