As to dropping stamina
IMO & IME, and based upon having done so in the T20 playtest, It'll toughen up the "young punks" considerably.... they won't go unconscious!
You lose the unconsciousness mechanic. That's readily fixable, tho: To Remain Conscious: Fort Save vs 3x damage taken to LB.
One extra roll, but no extra bookkeeping.
BTW, the twin system makes it so that:
Unarmored punk is dropped by even a heavy pistol
Armored punk stil drops, but won't be in the hospital.
Unarmored vet takes two, maybe three shots, keeps on coming, but drops dead with the fourth.
Armored vet sucks up 6-8 rounds before finally being beaten into unconsciousness inside the armor.
It IS worth the bookkeeping.