Buy a 23 and drop an extra $120 on a Lone Wolf 40-9 conversion barrel. Now you've got both!
Both are fine guns, and essentially identical. I have Glocks and am happy enough with what they are. The XDm is my polymer of choice, however. But nothing is going to be cheaper or easier to convert (if that's at all a factor) than a Glock.
"The Future is Unwritten"