Yes it does. During the later stages of the game it will mean you will save hours on building troops. In the earlier stage of the game it might not benefit you because either you don't have the resources to keep full production all the time or you only have a small amount of farm space to fill. When you are stacking 255 slingers in production from a full stock of resources, then having a 30 baracks and casting population growth will save a lot of time.
I agree with Lolophant, not quite as beneficial for the earlier stages of the game, but when you start to specialize cities, would be very helpful in a Ground Offensive/Defensive city to max out your barracks, which also means there are other building you wouldn't need to max out, such as harbour for example
