I have both a 23 and 22 and have shot them both in competition. They both shoot really well and are both very accurate for my needs. I have carried both of them and tend to favor the 23. True the 22 has a capacity for a couple more rounds, but the extra length on both ends just makes the 22 harder to worry about in the carry department. Also, in the competition I use to compete in, I know many shooters who shot the compact sized GLOCKS and carried those same guns as well as their personal preference. One thing I did almost forget to mention is that from 23 to 22 to 35, the slide and barrel gets progressively longer and so does the sight radius. This means that, the longer the slide is, the better potential you have for better accuracy. But again, you have to consider weapon size and how easily it will be for you to conceal.
IMOP, I would suggest going with a 23, and if you wanted extra capacity, just get some 22 mags to use with the 23. Hope this helps.