One more, just some math.
A -10G impact, an average man weighs close to 1 ton. The seat gets about 220 lbs -- guess my sliders can handle that....
That was the front impact.
Now the the rear impact - +10G (not talking about the remaining mass energy forward), without any headrest the survival chance is slim to nothing...sorry.
Yes the seat sliders could brake in this scenario, would be sad to be on the stairway to heaven with a broken slider....
Take it easy.