Pierce (in his prime) is what you would have if you took Turner, made him bigger, stronger and more physical and he played fundamentally sound in-control basketball.
Turner's best and worst quality is that he's a crazy out-of-control guy. That means that he makes stupid decisions sometimes, dribbles his way into trouble and doesn't know how to get out of it, but he's also not afraid to just go at guys and make plays in the lane.
Guys like Pierce who have the talent, the crazy confidence to play fearlessly and also stay in control and have great attention to detail are VERY rare.