the phase III ONLY happens to ny police, enough said.
Actually, there have been Phase III type failures other than the NYPD. They are just more obvious there because of the large numbers of G19s in service and detailed tracking/documentation.
the .40 kaboom, internet lore.
Not really. Maybe not as common as one would believe based on the internet but definitely happens and has been documented.
never heard of the .45 frame problem.
This was pretty well hashed out over on Glock Talk (with no denials). Seems like it was a rather minor problem when Glock had a small run of bad frames that resulted in minor cracks around the serial number plate. It involved G29s as well (same frames) and did not cause any functioning problems.
The G19 has had some other fairly well documented problems early in its life including a tendency to slam fire (and even go full auto). It also "disintegrated during the DEA's "frisbee testing"--throwing/sliding it across a parking lot (not a totally unreasonable test for a proposed law enforcement weapon). These problems have been pretty well addressed by Glock's "voluntary upgrade," but there might still be a few "original issue" weapons out there.
If I had to pick a "must absolutely work every time" Glock, the G17 is a no-brainer.
FWIW, I have had two Glocks (out of several) that can only be described as lemons. One a G23 that was just plain inaccurate--nobody what ammunition, whether from a rest or not, it just plain would not shoot a group--it though bullets all over the place. The second was an early G31--it could not get through a magazine without numerous failures to eject--I tried four different mags and different ammo,and it just wouldn't work--my guess was it had the wrong extractor (a relatively easy fix, but it shouldn't have happened).