I don't always carry a reload with my G19; it doesn't really bother me, I figure 16 is enough to exfil my wife and I. Would another mag be awesome? Yes and I should try to carry one more often but I honestly can't see it being a game-changing factor. The Pocket Shield I run my light from has an open Ten-Speed pouch that I'll put a 17rd in.
I think the biggest change that I have done is the addition of a SWAT TQ or a "Pocket DARK-mini" from Dark Angel; Westgate changed how I approached a lot of activities.
And of course, sometimes I"ll just have my J-Frame, a light, and a SWAT TQ on me and I don't feel less able at all.