As a general rule, I prefer a 3/8x11 pin, with the joint being flat-faced. However, I have a cue with a piloted SS 5/16x18 pin that plays every bit as well as a flat-faced 3/8x11.
I think more important than the joint type or pin size is also the woods used in any given cue can dictate which pin might provide the optimum feel.
I also feel that certain makers have honed in their focus on a particular pin and joint type, and that is what makes THEIR cues play as well as they do....Keith Josey and his use of the Radial pin/flat-faced joint is but one example that comes to mind. Another would be Dennis Searing's piloted 5/16x14 SS 1/2 joint.
As I have gotten older and wiser I have come to realize that it's more about quality construction overall that dictates how well a cue will play...and that by overlooking certain cues because they do not fit into a preferred pin-type, you are doing both yourself and the maker a disservice.
Lisa