I'm hesitating over TheBrain somewhat less than I was.

What has struck a chord with me is Steve's description of it as a "primary project dashboard". In other words, it sounds as if it could perform the function of project "front page(s)", with the heavier lifting (to mix metaphors) performed by, say, DevonThink or the Mac Finder itself, effectively behind the scenes. I do need some such tool, in order to enable me to (mixing metaphors again) distinguish the wood from the trees.