I have played with the magnitude slider but it didn't seem to do all that much. I guess I need to work through it a bit more. I haven't purchased it yet, so I only have the initial 3 catalogues, don't know if that's the reason.
By the way I've attached a screen shot showing my depressingly small window on the sky from my back yard
For those who don't know, the green represents my horizon including buildings, trees, etc.