I have had a Kaeser 30 CFM unit (7.5hp) for four years now (over 8000 running hours). It gets regular maintenance for oil and filters on an annual service contract from the supplier and the only part needing replacement has been the solenoid on the unloader valve.
I recently bought a second one because we had added machines so a single unit could not keep up; actually for about a year the Kaeser was running at 100% capacity with an ancient Atlas Copco backing it up when needed.
The Atlas Copco incidentally has 45,000 hours on it and it still gives 45 CFM out of a unit that could originally do 60 CFM.
Both the Kaeser and Atlas Copco are the type that have the motor running constantly with the compressor cycling betwee idle and load; this means you do not have frequent large starting loads.
An open mind is a virtue...so long as all the common sense has not leaked out.