Most fatalities in "otherwise survivable" accidents seem to be head injury related. Other than stall speed, I don't really see how one construction type is better or worse than another? I suppose tube construction may compess a bit more to obsorb energy, but in accidents where the airframe is substantially compressed the G forces are such that survival is pretty iffy anyway. A helmet is probably the best aid to survival but I must admit I don't wear one. Next to that (discounting a parachute) is a decent memory foam cushion to help reduce spinal injuries.
SS