any experience with dual spectrum CFL (envirolite type)?

Has anyone used the dual spectrum lights that are on the market now? I've read lots where nearly everyone says to flower under a HPS. I have a 400W HPS but it costs a fucking fortune to operate. I'm on the lookout for a cheaper path (that isn't stealing electricity).

I run my 600 12 hrs a day for 30$ month roughly.
I figure I need 6 plants under it to make it worthwhile.
I started with dual spectrum it works.That 400 will pay for it self.