Lack of algae

[marie]

It's growth uses up nutrients that other algae might otherwise use and other algae are less likely to attach to coralline algae then they are to bare rock.
As far as looking nice, thats a matter of opinion

when it gets so thick it can no longer hold itself up, it looks pretty tacky

Sorry for the crappy photos I was fighting reflections but this is what I mean, these is pics of the back glass and one of my overflows