The only way I can say for sure that it's an advantage is that three bars is better than one. This week we had some internet problems, and the speed slowed to a crawl. I was stuck with one bar in Black Ops 2, and it seemed like no matter how many bullets I put in someone, I NEVER got a kill. At first I thought I had just not played for a while and that I sucked now, but it was immediately apparent when the speed started climbing again. It was kind of magical. It was as though I had spent days shooting pellet guns at my enemies, and was suddenly given a minigun instead. Though I can't say if three bars has an advantage over four. I hovered on three bars for several games before it finally sped up completely, but I didn't really notice any further difference once it did.
"In the quiet words of the Virgin Mary, 'Come again?'"