Anyone have experience with longer barrels on CW9/S9/P9?

Examples: 4.5" or 4"

My goal is really just to increase velocity for use with 65gr copper rounds, and the longer the barrel the better.

Some concern about the nut on the 4.5" barrel causing snag on draw though, and with no thread protector jacking up the thread and just looking a bit odd. The 4" alleviates that issue, but I wish it were longer, and the fact that its ported means its probably not offering much more velocity than the 3.6" one.