I've owned a few over the years. P226 in .40, P228, P229 in 9mm, P239 in both 9mm and .40. My last purchase I still have, a P229 in .40.
One of my best friends has been a cop in a small NH town for 15 years and his duty pistol has always been a P229. It's not something I would consider a duty pistol but he's not exactly going toe-to-toe with Crips on a daily basis. I've carried mine concealed and I have no complaints about it, though my preference is my Beretta PX4 9mm for temperate weather and my S&W Shield .40 for warmer weather.
As far as duty pistols, when I had a choice I carried my H&K USP .45 full-size. Though if I was limited to the P229 I certainly wouldn't feel undergunned with it. And if at this point you're wondering which caliber I think is best, my answer is "whatever chambering happened to be on sale when I walked into the store."