The diaphragm pump is much better than its reputation. What you should look for is the correct diaphragm dimension and pump performance. This should be more than 5.5 liters / min to be able to process even materials at cool temperatures. The big advantage of the diaphragm pump lies in the simple operation and above all in the cheap spare parts. Maintenance is much easier compared to piston pumps.
Diaphragm pumps will also further pump, if you do not spray paint. At very hot temperatures, the color in the membrane can harden. Therefore, it is recommended to stop the machine if no paint is sprayed.