I have a 19 which is the same frame size as the 23.
Basically if you have an average size hand, when you hold a G22, or G17, there is a half inch or so of grip left untouched at the bottom of your hand. On my 19, my hand ends where the grip ends.
For me, it is a perfect fit.
That's 9mm though. Recoil is easy to control. .40's have more snap, so a shorter grip, and slide might make it tougher to shoot than the 22.
Try to shoot one yourself before spending the $1k if possible. They are pretty rare though. Barely see other 19's, and have never seen a 23 in person.
Another point, I don't really like gen3 19's but LOVE my gen4 19.
The different backstraps on gen4's help tailor it a bit more to your hand as the gen 3 19/23 is fatter around the thumb than the gen 3 17/22.