To further answer the question:
Apart from weight, an EDGE stock is constructed from an inert material. A wood stock is much more prone to expanding and contracting due to temperature and/or humidity. In my case, I work on rifles in California. When I get to Montana, temperature differences can be 100 degrees or more. That affects wood. Humidity will not vary so much, but I promise if you hunt Alaska, coming from the desert southwest means a big humidity change.
Pillars are intended to keep the stock material upon which action screws bear from collapsing and compressing over time, which adds a (significant) variable to the stock/action interface. Suffice it to say that you want a stress-free action, and if your stock material begins to compress or deform over time, you will play hell keeping an action stress-free. Pillars were developed to address this in wood stocks. So you can pillar-bed your wood stock. I pillar bed all my personal rifles, most of which sit in McMillans.
The following does not apply only to EDGE, but I would say that, for me, the biggest advantage to semi-custom rifles (with aftermarket stocks) has been rifle fit and balance. Yeah, I appreciate the (generally) better accuracy and cool custom factor, but really, at a (not too) un-standard 6'2" and 215 pounds, factory rifles at standard LOP simply do not fit me well.
McMillan normally allows you to find a pattern that works well for your body type, built with the correct LOP, and yes, if I am also barreling an action, I can then factor in barrel specs to get the type of balance I want in my rifles.
So, for starters, ultralightweight, inert, pillared, properly-fitting, and let's not forget, aesthetically pleasing improvement over factory wood (not to speak of Tupperware) stocks. These are some of the advantages of EDGE stocks.
I still think they are the best on the market, assuming you find one that fits you correctly.
