I have one fitted to my P-bass (a Stellartone Tonestyler).
It's good, but I found it a little honky at some settings, but tweaking my amp's EQ a bit eliminated that issue.
As far as how much I use it... there's two ways to answer that question:
1. I have found a setting that I like and don't move from there, so , technically, I don't use it any more.
2. It's fitted to the bass so I guess you could also say that I use it all the time!
'80 Rick 4001. '84 Fender Power J Special, '05 USA Jazz, '11 USA Precision, M Miller Jazz. Peavey T-40, Zoom B3. GB ShuttleMax 12.0, GB Uber410, fEARful 212.