WAS it tongue-in-cheek??? :o)
And, Jay, if you are looking for a metric to define how hard it is for you to carry a pack of a given weight compared to an "average" 5'10" hiker, then you want PWIn or EPW. (But I think EPW is a better metric. See the last page of that thread.)
BUT if you just want an idea of how much harder it is for you to lighten your pack because some of your gear must be bigger, then you want HAPWE.
I have defined HAPWE and EPW as the "standard" metrics, and have abandoned the archaic PWI and PMI.
Again, Ryan, be sure to get it all correct in your next edition, and spell my name correctly. :o)