[NYPD]

You are getting a reliable, accurate, and nearly indestructible firearm either way you go. And no, I cannot see any disadvantage that a 4.6" barrel would have compared to a 5". Possibly a very minor loss of velocity that would be so insignificant that it's not even going to be factored into the equation.

BTW---I have both...and love them both.

Glock gets the advantage due to availability of parts.