I remember talking with a former (East) state cop who was on his agency's equivalent to swat many years ago, back then the P229's were first available. He said they were decent service pistols, once the company was able to send them a couple hundred new trigger bars for the first shipment of guns. He said the first batch of guns decocked themselves instead of firing in DA, and the problem was eventually traced to improperly machined trigger bars. He said it took longer than expected for the company to get them replacement trigger bars, but otherwise the problem was eventually resolved and the subsequent weapon shipments were good to go.
I once discussed some problems with the rangemaster for a large agency (more than a thousand sworn), regarding some erratic accuracy issues being experienced with another company's .40 service weapon. (No name, but it's owned offshore.) He said the gun company blamed the ammo company, and the ammo company said there was nothing found wrong with the ammo, but the guns were still experiencing wildly erratic accuracy. The rangemaster believed his armorers had traced the problem to something about barrel manufacture, as the "problem" followed specific barrels when moved among different frames/slides. He also said the gun company's engineers stopped returning his calls. The agency got rid of the problematic guns and changed to P229's (and were satisfied with them for at least the few years I kept in touch).
I've heard of other large and small agencies reporting "problems" with one or another of the gun companies, and changing makes/models ... and then other agencies going the opposite direction, claiming problems of their own with brands other agencies saw as the "solution" to their "problems". Go figure.
Sometimes "parts is parts" duty pistols may experience a problem with one or more of the parts (and assemblies) used in the guns. Sometimes it may be able to be solved at the filed armorer level, and sometimes it may require the gun company's field armorers ... and sometimes it may require replacement of the guns, or even going to another company's guns. The world spins round ...
BTW, I remember the NJSP "issue" with the SW99NJ (that was the specific model name S&W made for the state agency, due to a modification demanded by the agency, over the objection of the engineers).
One of my SW99 armorer manuals is from that time, and lists the SW99NJ variant in the manual. I remember being told by the armorer instructor of that time that S&W had sent the SW99NJ's reported to be problematic to H.P. White Laboratory, for outside testing, along with some ten's of thousands of typical duty loads. We were told that the lab was not only unable to duplicate or observe any feeding/functioning issues, but the observed “Mean Rounds Between Failure” (MRBF) was considered excellent. Subsequent factory in-house testing also revealed an outstanding MRBF for the model. The company took back the SW99NJ's, though. There was some mention of some possible political and union concerns. The world spins round ...