regarding spraying: I do think it gives the best finish (especially with shinier finishes), though there is some amount of technique to it. The majority of the work is in prep: sanding, filling imperfections, sanding some more, and masking. I painted the entire interior of my house. A single coat for the whole thing took about 45 minutes. Masking beforehand took a week. Don't underestimate the amount of time it takes to mask and the amount of mess that will ensure if you don't.