As I understand it this was an issue with some of the earlier generation 3 G-23s. And it is also my understanding that the problem was corrected and the ones after that were alright. I have a G-23 with nearly 6,000 rounds through it (all factory fresh ammo and no solid lead or semi jacketed bullets) and I haven't had any problems of any kind.
I had heard the same thing when I was looking but, I'm pretty sure it was the early Gen 4 that had the issues. Either way, I have the Gen 3 Glock 23 as well, and have thousands of rounds through it with out a single issue. It shoots straight and that's my main concern. I don't really have an issue with the ergonomics of it at all, maybe because I have big hands. I think it's more comfortable then my 22-45 (1911 style).