The advantage of a McMillan besides a slight weight savings are several things.
Mainly strength against accidental spills as mentioned. and the assurance of your zero not changing like what can happen with wood stocks. Yes there are wood stocks that are damn near as stable as a McMillan but still if you want a dead reliable rifle a good stock like a McMillan help tip the odds in your favor.
They are also easier to repair cosmetic issues from the bumps and dings that do happen.
Also switching to a McMillan is an opportunity to get a stock that the ergo's are better for you. like the length of pull, the pistol grip shape and so forth.
I have a pre 64 270 FWT with a Compact Edge and I really like it.
Still I have some pretty wood rifles I use but I carry the Mcmillan stocked rifle more.
