retrolefty:
That is a valid design but it really should utilize a cap that is designed and rated for direct mains connection, not just that it's working voltage is high enough, but that if it does fail it fails in a safe manner.
I've used general purpose metallized polyester types and they seem to work with no problems. Not sure why they wouldn't be suitable, but I can't disagree, better safe than sorry.
Is there a particular spec or type that should be used?