I think you did good. IMO, everyone that works on their own stuff should have at least a compressor like that for all-around use. Other than running your paint gun, it'll run air nailers for carpentry forever as well as impact guns and die grinders for mechanical work. Having good pressure and volume for more than the 10 seconds a pancake compressor will provide will be really convenient for a blow gun and airing up tires.
Just keep that tank drained and the compressor powered off when not in use. I had a 30-gallon oiless Craftsman that I kept powered on because it never leakedd. I came home after a weekend away to find my garage freezer thawed. It was packed with deer, beef, fish, pork, shrimp, crawfish, etc. so it was a big loss. The compressor developed a leak and ran so much that the motor burnt up and tripped the breaker, killing the freezer with it. I salvaged the tank and converted that compressor to a belt-driven oiled design with a compressor head and motor I scored off Craigslist and copper tubing and fittings from Home Depot. I also made that garage receptacle a dedicated compressor circuit.
Oh, and I reworked the shelves in my pantry to put a chest freezer in there. Inside the house is a MUCH better environment for a freezer. I don't ever wanna endure such a meaty loss again.