Can come out as beautiful as a liquid coating if the plant does it right.
Basically, the pieces go through a big conveyer belt steam washing line that blow dries them at the end. They are then hung from stiff metal wire hooks (different lengths depending on what's being painted) on a line that goes through the painting station. At the painting station the part revolves so it can be coated on all sides. The line itself is positively charged, the applied powder coating is blown from a special gun and is negatively charged (interestingly enough with the liquid electrostatic process, the paint is positively charged and the piece is grounded for negative). If the painter does his job right, a nice even coating of powder is applied, without excess or then spots. The pieces continue on the line on a serpentine path through a large oven that causes the paint to flow and bake on to the piece, the last part of the line cooling and hardening the paint. At the end, once the parts are sufficiently cool, they are taken off the hooks and packaged (this of course is on a large run...individual parts for a small order would generally be scheduled for the beginning or end of a run where they're already applying the color of paint in question, or are a one off with a specialized color).
If the process is done right from washing to removal from the line, the coating is indistinguishable from a properly done liquid coating.