Useful, but probably better with 3/8" nap.
"This roller paints vertical corners well with a moderate amount of skill and care. Avoiding a 1/4"-1/2" gap at the top of walls where they meet ceilings requires more skill than I've developed yet. For applying primer to new drywall, other than in corners, this roller is much slower than a high-quality roller with a 3/8" nap. The quality and material of the two rollers seems comparable, so I expect the difference is the 1/2" nap on the Corner + Roller."
