I wasn't actually comparing the calibers, although it might have seemed like that. My point was that if I wanted to carry a 18.5 lb weapon, there were better ones available. I don't want to get into the 30/06 vs. .308 dispute.
The BAR was great in its day. It was never considered a "combat rifle", but a light machine gun, with one being issued to a "squad" and carried by the "BAR man". An early antecedent to the modern SAW, I believe it was developed to give troops assaulting across no-man's land during WW1 mobile firepower. It shouldn't be considered a "battle rifle", like the M1, M-14, or M-16 that it's being compared too.
In its proper role, I'm sure it would be just as effective now as then, but there are better choices available. As far as it being a "good combat rifle", it never was one.