User blog comment:Lord Loss/Monster Appreciation Day: Lunastra and Teostra/@comment-1758220-20120121180337/@comment-969093-20120122105301

AuL is 20 * wep multiplier, so the impact it has will decrease as the weapon's Raw increases. A critical hit with a Bone Club won't make as big of a difference as it would when using Magnitude. I think it's pretty much so that as soon as the critical hit starts to make for more raw than AuL would (multipliers applied, = +104) that the importance of AuL over RA will slowly start to become irrelevant.

However, it doesn't hurt at all to have both skills at any time for any weapon. To be honest I was still debating with myself about this up to date while making custom sets for mhfu. But now that I have made this post, it all makes sense to me. -_-