Oil free also has a shorter life. But do the oil lubed compressors make the oil smell when you discharge the gun?It is difficult to tell the cams as the manufactures cheat on the specs as pointed out in the video Heinrich put up. Roachcreek
The belt driven oil compressor are usually quieter than oil free. My very old oil filled twin lung belt driven compressor 40 gal. is much quieter than my Bosch pancake compressor. I would think if you can get a compressor that honestly gives you 5-6 CFM you will be fine.