Sorry, bringing back a discussion from 5 pages ago ...
I've been thinking about this. Despite my earlier comments about really changing things around with the Finally, I think Nathan really is on the right path. A LOT of people like the Finally the way it is. He can already accommodate players looking for a little dirt or squeaky clean by simply changing the tube. Perhaps that should be an option listed right on the website (tube type) when you order.
If he can add a HPF and a separate volume for the XLR and 1/4" outputs while keeping the price and size the same, I think those are good additions to expand the usefulness of the product. If there is room, a LPF would be nice too, but if I had to choose one or the other, I'd take the HPF.