There is something else a power lam does that you don't hear much about too.
Besides pushing the working section of the limb out further towards the tips, it loads the fades more evenly and stores energy in the pre-load stage when you brace the bow.
This helps out a lot in producing early weight on the draw, and can produce a smoother drawing bow if it's used in concert with the right taper rates in the core, and tip wedges.