Well ... I've got to say that I love this idea. It is IMHO the most important feature that you could add to MC. However, no giant surprise, but there are definately some performance issues with some of these more advanced searches. I imagine you'll be working on that. My initial attempt was to create a View Scheme using a search that you suggested (to find missing files).
The performance is terrible (if it will be even remotely that slow you will need to warn users and provide some sort of progress feedback). As I said, I know this is an "alpha" feature and I'm not complaining. Just giving feedback! I still think the feature is worth it (even if you need to provide progress feedback).
I created a View Scheme in my Video View Schemes hierarchy. Added Genre, Artist, Album to the View Items (1). Enabled Populate Tree, Honor Parent scheme search (3). And I inserted the Search you gave as an example ([=FileExists([Filename])]=0) in the Search Field (4). It takes about 30 - 45 seconds to respond every time I click on the View Scheme in the Tree View (without even expanding it). Also, it apparently re-runs the search when you right click on it, as this produces about the same response time (before the right-click menu appears).
One other question I have is how you can combine the new search methodology with the "old" system. I ask because the search above provides all removable media, and I would like to filter those out (to display just those that are missing). Now granted, I haven't reviewed any instructions you may have provided (if I need to RTFM just slap me around) but my initial attempts didn't work (they filtered everything). I tried: [=FileExists([Filename])]=0 [Removable]=0
. What is the proper way to do this?