The G17 is a nice weapon.
How long does it take you to rack the slide with one hand?
Maybe it's paranoid, but I don't want to take the chance that I might have already been winged when I present my weapon. I can rack it with one hand if I have to, but it takes me more than a second. Most gunfights are over in 3 seconds, I'm not willing to give the BG that much of an edge.
Then carry a ruger or a taurus doulbe action revolver with transfer bar safety . Ready to fire at ANY time.