I use ATX power supplies on my printers. I do so because they're readily available and have gone through a relatively large amount of safety scrutiny for home-use (especially considering I only buy high-quality PSUs). Also I really like having a high-quality 5V source around as I use for things.
The rocker switch I use for the Delta Flyer has just hung aimlessly until now. Today I CADed-up a model for a casing for it and installed it. It looks absolutely excellent.