Go Glock! The G23 is the Glock compact .40 (the G22 is the full-size .40, used by many police departments). If you check the specifications on the Glock 23 and the Springfield XD Service model (4" barrel, comparable to the G23), you'll find:
- The G23 is a half-inch shorter in height,
- The G23 is about a half-inch shorter in overall length (despite having the same length barrel),
- The G23 is 5 ounces lighter,
- The G23 holds 13 rounds of ammunition, vs. 12 rounds for the XD Compact (both in .40 caliber).
Combine that with the legendary Glock reliability, ease of maintenance, many holster and aftermarket parts options, and the choice should be easy.
"Placement is power" -- seen in an article by Stephen A. Camp
(RIP, Mr. Camp; you will be remembered, and missed)