(wincing) "In theory"... Supposedly you can go up to 200% before you notice any degredation...

When I did it with the D100, it got noticeably softer, so I settled on 150% and it came out better while still being able to do a 2-page spread. Haven't tested out the D200 at 200% yet - I might play with that this week, I suppose, since I hadn't thought about it until you just brought it up.

Actually, the exact dimensions for the D200 are 3000x4481 (I was using the old standard that the D100 would hit when I typed 3000 for the short side) when I up-res with Capture. It's nice and clean, and I love the exposure controls (I'm sure this is common with all OEM software converters, but it's bizzarly extensive!) better than Adobe RAW - the only downside is that I'm in a 2-stage process where I have to re-save them out as TIFs and THEN open Photoshop for the complex editing.

Haven't really gotten into Lightroom yet, as I hear you can export directly into Photoshop, so that might save some time.
-Lew ;-)