Nursery for New Members

I was going to do it anyway, just wondered if there was anyone with a view or opinion on using bmx cranks. I'm also going to be running a front hope xc on the back with a custom made axle and a bolt on ISO sprocket from London Fixie Bike. Not really a conventional Fixed wheel setup, but from an engineering point of view, better in almost every way!?

Please post pictures when done/worked on (Current Projects is best thread for this). Would be interested to see this set up.