I play lots of bass parts on my keyboard, and I had my GR's feedback switch on all the time. I can't speak for how it affects bass guitar, but my keyboard loved it! It added just enough bite to lows, mids and highs. I'm glad it's still there somwhere!
I never thought of doing that. I recently picked up a Juno 60 and having trouble finding a suitable drippy filter patch. The GR might just do the trick.

