I have 22 petes, 6 estate system pipes, 3 new system pipes and the rest non-system pipes new in the last year. They all smoke well. The draft holes are all centered, but all are slightly high in the bowl. I have not experienced any issues with the quality. Despite the draft holes being slightly high and they smoke fine. I can smoke them all down to the bottom with no issues. I typically don't smoke a bowl down to the last bit of tobacco, as the last bit to me always is less than stellar.
Being that my Peterson experiences are from pipes that are either 15 years old or less than a year old, I can't speak to the pipes from 3-15 years ago. Typically that is the 'window' of time I see the quality questioned.
In closing, I have heard a lot of both Peterson praise and bashing. But, to me there is just something about Petes that speak to me. The style, the variety, the look, the seasonal pipes. I'm hooked on Petes, that's for sure.