I'm same height and 20lbs on you, and let me tell you, it's not easy. I ended up taking the bipod off because it makes it a lot harder to use, and it's still not what I would call comfortable to shoulder fire. See if you can borrow or at least hold one to get an idea of what it's like before you make your decision.
Yeah, shoulder fire is impossible for an even relatively muscle toned person like me, what i did when i used one at Revelations for a few hours was use the USGI M60 sling the guy that owned it had on it around my neck, and advance with the gun at my hip and i held the carry handle. Looked like a total badass and was comfortable.