it would be nice to add a column to show if files have album art in their tags.
i guess i missed this earlier... but i see i can add column "cover"
You can also set a filter for the field %_cover%:
%_cover% IS ""
filters (shows) all the tracks that do not have a cover/albumart.
set up a new column, name it "Cover" or whatever.
in the "Value" field enter "$if(%_covers%,Y,)".
this displays a "Y" if the track has a cover stored or nothing if not