CXC made a point in the 8x10 scanning thread - why scan 8x10 at all? It is total overkill for almost any form of digital reproduction, other than contact printing, or traditional enlargements. Same goes for other ULF sizes (unless you are that guy trying to make the world's largest scan, and get publicity in the NY Times...)
I think the last commercial 8x10 job I did was for a wrapper that went around a CorningWare package - it was 4/c 24 inches x 96 inches, one shot, of a panoramic still life of plates and casseroles. That was in the mid-1990s. It became too expensive to do, and most packaging is now one or two color screened images printed directly on the cardboard.
I also did a 30x40 poster with 8x10 in the pre-digital era (it was drum-scanned, but this was before Photoshop - early 1990s). I really doubt that you could see the difference between it and a 4x5 version, as similar posters done with 4x5 look just as detailed.
I do see a difference between 4x5 and 8x10 in traditional C-prints and Ilfochromes, but when you can scan a 4x5 to 300mb, why would you want an even bigger file?
Bookmarks