Both have their good and bad points. Powder tends to be thicker and a lot harder to remove if something get coated that isn't supposed to, while paint requires the additional step of priming before paint goes on and the powder process is just plain faster. Me? It depends. Restored the body on a vintage Indy car a few years back and the wire spoke wheels needed to be the same color as the stripe on the car (dark blue) I advised the customer to have them powdercoated as it would produce better results. They came out great, and except for those involved, nobody knows.You're right, it was cheaper than painting. Most of the cost was in the blasting. I had the swing arm done as well.
The real hassle was even finding a place to do it. Most of the PC places around my area wouldn't do the blasting.