I think its a no brainer, an opto kill adds another layer of safety to the most dangerous part of a plane - the big shredder at the front.

If your not convinced think of it like this:  whats worse to be hit by??? A fast gliding heavy plane that'll impact like a sledge hammer - or the same plane going three times faster with a two foot rotary cutter at the front. If you lose the radio link, this is the question you'll wished you'd have considered earlier!!!!!!!!!