UPDATE: Just ordered a Gen 4 G23. I have a new LGS with reasonable prices and fair trade-in values to boot. I traded a used Sig 2022 that I paid $389 for Three years ago, got $300 for it toward the new Glock. I could not have sold and shipped it and had a better net, so I am happy. He is selling NIB Gen 3's for $499, Gen 4's for $530, both are about $20 less than my local Academy.
I get the Glock in five days or so. After all the comments, I tried both the Gen 3 and 4 for fit, and it was not even close. The 4 was far more comfortable to my hand. The caliber switch is a bit painful given all the .40 ammo I gave to my nephew last year, but after a lot of thought and homework it is pretty clear that is the right caliber for this platform. Good power and reliability upgrade with only a 2 round penalty makes this a no brainer.
I had to seriously resist buying all the usual upgrades, I literally had the 6# spring, 3.5# connector and SGR in my shopping cart @ Loan Wolf, I deleted them all. I am leaving this OEM, with three very minor exceptions of an extended slide lock, extended slide release and a plug.
I am pondering adding the Glock night sights, my LGS will add them for $69.
Range report next week, hopefully.