Alt-K can display stats for All or Tagged files. I think it would be useful to also be able to show stats for Matching files.
For example, I have recently discovered a lot of photos scanned as png files scattered in many folders across a drive. These can be converted to jpg files with huge savings in disk space, so I'd like to know which folders they're mostly concentrated in.
The only current method is to use Showall to tag them, then use the Alt-K Tagged option. Having a Matching option would save a step, and avoid unnecessary disturbance of tags I might have set for something else.
[Note: Slightly related - I've just posted a bug under the latest zeta about Alt-K Tagged not working with dir mode.]