not completely
lets say from 29xx to ~3030 most factory new neural helmets will be the clunky ones (of various types)
by ~3030-3039ish an additional % (whatever makes sense in your campaign) start being newer models being phased in at some %/year
~3039-3049 newer designs are phased in at a pregressively faster rate
same from ~50-60
etc
by say late 60's the production of the old style "torture device" helmets are almost gone, except a limited production continues for "personal Preference" reasons, that and the stupid things are CHEAP
in the RPG
neuralhelmet std (AKA torture device) av's 4/4/3/2 6kg, -2 perception penalty, encumbering 900 cbills
neuralhelmet combat av's 2/3/2/1 5kg, -1 to perception, encumbering may be sealed in hostile enviornments 1hr air supply 1400 cbills
neuralhelmet clan av's 2/3/2/1 3kg 5000 cbills