It depends on the person's personal preference really and what they're wanting to do.
For me since i'm 5'5 and was rather skinny (135lbs) I was sick and tired of being thrown around the damn soccer field by someone just batting an eyelash at me... Literally when someone would go 50/50 on a ball with me shoulder to shoulder i'd go flying. I was sick of it.
Now that i'm a tiny bit bigger (165lbs) I can fight a little bit more. I do notice that if i do not stretch out before game though it's MUCH easier for me to pull a muscle.. Where as before i didn't really have to stretch at all..
Also, being bigger does help me for when i play lacrosse too. I don't have to spear people nearly as often to try to tackle someone.. Sick and tired of getting flagged for spearing
But it's what i have to do to compete so... Being bigger is a must for me.
Now what i really want is to get size 47" chest so i can just flex them and make people fall back over themselves on the soccer field, but i doubt that will happen ;) hehe