Anyways, on topic.....I don't think there's anything to be gained from going over 10-12%. Strength wise maybe, but not for muscle gain.
Lean muscle takes a LOOONG time to put on. When you don't see the scale move like you want, the natural thought is to eat more. I think time/consistency is the most important thing. Train hard, eat 200-300g protein/day, juice, and stay as lean as you can without killing yourself.... the muscle will come with time