Went into a shop today and tried a small (5" x 3"x 3/4") PLL AM/FM portable.
Tuned to a local AM station. Audio excellent for the size of speaker. Tuned
up 9Khz and station still there, very much audible, with a bit of splatter.
Tuned up18Khz from station, station still audible, but much slatter. Gosh,
they make the AM filters wide these days don't they in your pocket
portable!

I suppose that in practical use as a non DX radio, the wide bandwith has
little significance. Not likely that another favourite station is going to
be within 18Khz. Audio quality over selectivity obviously. You feel that
the radio you are listening to is a peice of junk because of the wide
bandwidth, but I guess not, if it gives such good audio quality for such a
small size.