I have two SIGs a P220 .45 and P229 9mm and find them to be very fine handguns. I suspect you would do well with a P229 in .40 caliber, but if you are happy with your 9mm Glock it might make sense to simply get the G23. However, even though I own a Glock G20 in 10mm and am in no way anti-Glock I do feel the SIGs are a little more refined.