For me... spraying the paint is the "easy" part. Sanding and body work is the part I hate and am not very good/efficient at. I HATE SANDING.... I have succesfully painted several cars, airplanes and motorcycles over the years.
Small stuff like motorcycles have all come out perfect as sprayed. But most of my larger stuff has required additional sanding and buffing after painting to eliminate orange peel. I HATE SANDING.... I HATE BUFFING....
Bikes come out perfectly smooth and glossy with no sanding buffing required... Cars... not so much. lol
I have used various brands of expensive primers/paints both single stage like the old Imron and Nason along with a bit of base/clear on a couple occasions. I have tried expensive borrowed guns but most times I have ended up using a cheap gravity type gun from Harbor Freight.
I consider myself fairly decent at being able to learn to tackle any DIY task, but body work is definitely my weakest DIY skill. PS Did I mention?... I HATE SANDING!