I have sent hundreds of gallons through airless systems, including lacquers on doors and cabinets. They work great for what they are designed to do. Their best use is latex paint on walls and ceilings. They do OK for cabinets and doors, but very tricky to use and not get buildup and uneven coverage. The paint comes out very fast. It can be adjusted, but then the finish quality goes down. Having a 25' hose takes quite a bit of paint and that gets wasteful and expensive.
If you are talking about one of those Wagner type $100 units with the paint container attached to the gun, I have no idea how they work other than a friend who works at HD said they get a high percentage returned. You could always buy one, try it, and HD will take it back so no risk.
For priming, the HF HVLP guns work so well and are so cheap, I used them for priming and got the 3M with disposable tips for the finish paint.