Check out the latest version of Papers here:
The full screen notes HUD for adding notes to pdfs reviews is very neat.
I can’t… it hurts me too much to look at it.
looks anyway
Ohh… the pain 
Hurry up, DTP2! 
I’m reminded of the muppet song, “It’s not easy being green”.
It’s not easy to satisfy everyone on UI issues, either. Sigh.
What they have done (in effect, whether or not they’ve ever heard of DEVONthink, much less downloaded it) is comb through the forums, found all of the wailing and gnashing of teeth for UI/feature improvements to DT, and then acted on those suggestions. Papers isn’t any prettier than DEVONthink – I actually think it’s downright unpleasant-looking, and I could (and will, if you call my bluff) rant for at least a good five or six pages about what’s wrong with the app purely on an interface level. But it’s a damn fine 3-pane+info view, as far as having all the features and metadata laid right out in front of you. And I’m a 3-pane+info kinda guy.
Is that really good User-Interface design?
It is VERY, VERY busy. There are lots of embedded toolbars. More is not necessarily better. And Papers, to me, looks like major-league overkill.
I have some issues with DEVONthink’s UI looking a bit dated, and I would like to see better smart groups as opposed to the current scripted smart groups, but Papers is way over the top and would be more than I’d want.
Oof.
nods I can’t think of a legitimate reason to have the iTunes-esque “Filter” (All|Flagged|Unread, All|Articles|Reviews|etc) in DEVONthink. DTP is too versatile for a meaningful application of any specific set of buttons there, and if you went by keywords there would be an entirely different can of worms.
I prefer having the toolbar at the top, and although I posted about DEVONthink adopting a “per-document” toolbar scenario much like Papers has, I’ve come to reconsider it. It is ugly, cramped, inefficient on lower-resolution displays, etc.
I am very attracted to the integrated information panel, though, and I lust after tabs (even though I don’t like the way they look), the keywords, nestable smart groups, etc. And, as Milhouse has pointed out, the fullscreen UI is pretty sweet.