Quincy compressors are or were well regarded as excellent quality for many many years.
The QR series I believe is what earned that reputation. They are heavy, run slower than other brands might, so quieter and last longer because, and they have internal oil pumps and often external spin on filters. Industrial quality all around. They usually have unloaders too that work on oil pressure and before oil pressure builds at startup or if pressure is lost they unload and freewheel for easier starting, longer life, and to reduce damage if run out of oil or other oil system failure.
The QT series are a somewhat newer offering as their more affordable line with fewer of those good design features. They may not all be US made compressors?
The recent QR series are similar to the good ones of old but have fewer cooling fins on the cylinders and rumours of not being quite as good as the old ones.
I have about 6 Quincy compressors, two of the cheaper QT series, 3 older and one newer QR series with the oil pumps. All good compressors.
