Regen. It had quick recovery; Not only was it better than stamina, but you could get it a whole heck of a lot sooner.
IIRC, they based much of CoH on pen & paper games, (Champions?), and so seemed to have implemented the combat system in a turn-based-like fashion; They probably didn't expect people to spam attacks as fast as possible, and instead expect 1 hero to trade blows with up to 3 minions until 1 side was defeated.
A lot of my earliest memories consist of firing off a ranged attack from max distance, retreating around a corner, and taking on 1 or 2 enemies as they came to me. I remember using hover in lieu of knockback protection for many character's early careers, and trying to keep my TOs green. I remember choosing character origins based upon which DO shops were the easiest to get to at level 12, and heavily slotting only acc and end reduction, until I got stamina. I recall buying blue insp's a lot back then, too...