The system would have to have a reliability of one! Get real. Tell me a system that is that reliable.
Ordinary ejection seats aren't. That is why they have canopy breakers on the top in case the MDC fails to shatter the canopy or the canopy fails to jettison.
A helicopter system could have that kind of redundancy i.e. a way of going through the blades if they fail to come off!
The top and bottom of it is, that anything is worth a try once you get into a situation which is that terminal.
Ask yourselves how many people have failed to survive a normal ejection! That doesn't put me off sitting on a bang seat.. . <img src="smile.gif" border="0"> <img src="eek.gif" border="0">