Welcome to the world of affordable high-pressure air. My Yong Heng has accumulated a total run time of more than 7 hours over the last 1.5 years without any significant issues.
I did not use any expensive oil but just #46 hydraulic oil recommended by the manufacturer and also #100 compressor oil. Both are inexpensive stuff from China and I could not see any significant difference. I have recently examined the internals of the compressor and could not see any signs of wearing so I think I will keep using these oils.
Yong Heng has the unique advantage that parts are very cheap and widely available. Furthermore, the manufacturer keeps monitoring the feedback from the market and upgrade parts having significant failure reports. The improvements they have made to the first-stage and second-stage pistons are examples. The life of the machine can therefore be indefinite as long as you are willing to replace parts by yourself. This is your first Yong Heng and I doubt if you will need a second one.
However, you do have to go through an inevitable learning process but that's not hard given the simple construction of the machine.
