^ What?!
I would fail to see any argument where a sound fit of upper and lower WOULDN'T be a benefit.

I guess by that rationale you also would not need to firmly secure your barrelled action to your glass bedded stock on any bolt gun?
First off, I said "any play in the upper to lower match up" where the hell did that jump to an Accu-Wedge being the end all beat all to accuracy??
Second, since you brought it up, the sights are mounted to the upper, but you hold and shoot by the lower ( Pistol grip ). If the upper and lower move in relation to one another, your sight picture can change relative to hold.
Now, the annoying rattle aside, which I personally don't like anyways, the housing of the upper and lower are
aluminum. The pins that hold them in place are
steel. If they rattle back and forth under fire you have a wearing of dissimilar metals - guess which one is going to lose that battle.
Sam has two Stag parts, an upper and a lower, but from different end vendors, even though they are from the same company. While they could have come down the production line together, were seperated, and now are joined again in a holy union - but I kind of think that is unlikely. The gun shop near his house could have had that lower for a year, while the upper from Stag could have been produced last month. Any number of variables could have happened at the production facility in that time.
A little slop in the upper to lower match up may not affect him, or you, or anyone else on the forum, but I personally don't like any variables when a fix is easy and cheap.
For the record, I said an Accu-Wedge was $8 - it's $1.99 at CDNN, so even with shipping you are under $5, which is less than 1% of what he spent on the weapon. Hardly throwing money away in my opinion.
If you have a rifle that is shooting 6 inch groups at 100 - installing an Accu-Wedge isn't going to cut that in half. It will save on wear and tear between pins and action, it will keep the rattle down, and it might even improve your overall accuracy if for no other reason than you think it will. But don't buy it because you want to take the title at your local gun club....