It seems to me that you already have the home defense gun covered with your duty weapon. The G23 is a fine weapon and will serve you well.
Thought 1: Stick with what is familiar. Get a G27 and you have a compact gun that utilizes your 23 mags. You would have to get used to the 40 cal.
Thought 2: Make a big change to a very compact gun. Go with a Kahr PM 9mm. Very small trim gun with a lot of holsters available.
"Patriotism is supporting your country all the time, and your government when it deserves it." -Mark Twain