Just in short:
I think it is very uneven when you compare the regeneration rate in terms of veterancy and upgrades.
when you use your gun accelerator you can only gain as a cybran more hitpoints in making veterancy and/or using the backpack (cloaking).
if you chose the other way, to upgrade with tech II and III, you get instantly more HP and a better HP generation. and it is not even twice as much mass and energy you have to put in here.
when you now try to overcome the shortage in killing enemies with your better gun range and increased shots per seconds, you have to kill hundeds of enemies!
when you are lucky, you kill some dozens, but meanwhile the other tech ACU has upgraded to T3.
There is no good usage to this gun upgrade.
what do you think? i have no time to say it clearer. thanks for reading!