I have a 23 too, you would be very happy with it!!I am very seriously considering a 23 but if it was a end of the world scenario it would probably be the 17 for me.
I have 2 and the 21 is my favorite gun, I love my 23 but the 21? YEA BABY!!!I've only got one and I chose the gen 4 g21 but if I could have 2 I'll take a g30 also