Flex watt is cheaper in the short run insofar as purchasing cost. Flex watt and RHP's are somewhat similar in electricity usage though Rich thinks that maybe RHP's will be a little less to run.

I have had a strip of flex watt poop out on me after a little less than a year of usage and that was a drag. I have not had any of the RHP's give me any issues at all.

For me, in my cages, it's RHP's all the way