Dam, researched this on the web and learned something. I keep reading that it's not recomended for anything but range time and tends to throw brass straight back, but it works. I didn't think the 40 extractor and ejector would work on a 9mm case at all. Have you considered a .22 conversion for the Glock, way cheaper in the long run?
I would never carry anything out of the 23 except for the 40 S&W, but like I said it allows me to shoot a bunch of stuff on the range. I am looking to get a 22 conversion too.