What he said. The 239 is really as good as it gets. Handles +P+ (9mm), compact, accurate, extremely well made. Doesn't mean it is better than everything else, but when balancing concealment, reliability, accuracy, hitting power, capacity and quality, its a match for any gun out there.
Some people are put off by the 8+1 capacity, but really, this isn't the movies. You're responsible for every round, so the firing of dozens of rounds at multiple BG's just isn't going to happen. Can't think of a CCW story where this has ever happened. But, hey, even if yo are the first, spare mags are easy to carry anyway.
Bottom line is, you are more likely to carry it EVERY TIME, rather than leaving your bigger hi-cap at home.
Hell, the thing even fits in a decent sized pocket.
If you really do find yourself in a situation with multiple BG's all carrying hi-cap Glocks either:
1) They will run like the cowards they are as soon as you start shooting.
2) If there really are more than two or 3 bad guys, and they are that determined, you are going to be down before you get any further. Unless you find cover. Thats where your spare will come in handy.