The Ruger GP100 is one of the all time great heavy duty service revolver designs, and for the past several years, they've come out of the factory with very smooth actions as a rule. They've always been inherently accurate, and should serve you well.
Mine is a 4", and I've generally used it with a Blade Tech holster for competition, and a Ted Blocker holster (IWB) or a Derry Gallagher (OWB) hip scabbard. All have served me well.
Just one guy's experience,