I did use it but on my accelerated A1200, using FBlit.
It's perfect for Workbench usage for those who do not have a scandoubler.
It doesn't flicker and the refresh rate I can't remember, it should be mentioned in the SCREENMODE software!
I used to use Productivity @ 32 Colors and is a very recommended setup for those with the 23 pin Amiga Video to VGA 15 pin adapter, an 030 with a bunch of Fast RAM and FBlit, for as long as Workbench applications are concerned. I even used a Mode Promotion software to make some apps use this screenmode instead of their own PAL screen. Some work, some don't, but all in all, is awesome.