I'm pretty sure the McMillan F Class stock I use for .223 F/TR is stronger than the Boyd's laminated stock I use for 6mm BR F-Open class. So if you're gonna' use it to club a black bear to death, go with the McMillan.
But when it comes to shooting, the McMillan is NOT worth 6 times as much as my Boyd's, at least in my opinion. Plus, the McMillan took 18 times as long as the Boyd's to arrive at my house. So if you need a stock quickly, the Boyd's wins.
As far as I'm concerned, there is no functional difference between the two, so next time I build a competition gun, I'm going with another Boyd's. I'm pretty sure I've purchased my last McMillan. They aren't bad, but I don't see any reason to spend a lot of extra money and wait nearly forever to get one.
Incidentally, when it comes to shooting matches I usually finish higher with the gun equipped with the Boyd's stock; however, it's hard to say that the stock actually makes any difference. It's very much an apples/oranges comparison. Nevertheless, I certainly don't feel that I'm at a disadvantage on the firing line with my $109 Boyd's stock.