Had a good play over the last couple of days, and in the Lothians, where there are a number of channels I can't hear any difference with the DX/LO settings or the Wideband AGC.

I do think the IF2 bandwidth makes a slight difference (on Radio 1, 2 and 4) the wide setting sounds 'better' - the sound is just a little richer (very slightly, and sometimes I was wondering if I was imagining a change, but it seemed consistent with that setting)

Hope that is of some use