We of the Royal Signals have had name tags since I joined in 86. Pretty much the only Army Corps to mandate them Corp-wide. I don't know why though!
Taken as a Corps, there were too many people to know everybody, even in one's own trade circles. But in a regiment, or squadron, everyone knew each other. I didn't mind the combat jackets, shirts and woolly pullies, but it looked bloody stupid on the hemet cover when the Kevlar ones replaced the battle bowlers.