dawg23 got it right about buying both. Have had a Glock 23 for a couple of years, and just picked up its baby brother (G27). Both have night sights, and the 27 wears Pearce +1 extensions. I like the 23 a lot, and the smaller package 27 is only slightly thicker than the Kel-Tec P11 it replaced. Guess if I had to choose today I'd go with the 23, as I've several thousand rounds down its tube, while only 50 thus far through the 27. But I'm guessing the 27 will get carried more in time.