Whereas I agree with the general premise of what you guys at talking about, actually there is a big difference between the bullets initially mentioned.
The Silvertip is a conventional bullet - nothing really fancy about it. The FailSafe, on the other hand, is kinda like an X-Bullet in that it not only retains almost 100% of it's weight, but it penetrates (or overpenetrates) like heck. The Accutip has a plastic insert (which is so popular these days), but does not retain weight like the Failsafe.
Again, what both of you are saying is generally correct, but there is a noticeable difference when the bullet actually hits and goes through the animal. On deer, the Failsafe is, in my opinion, just too much and thus overkill. The Silvertip, as a conventional bullet, is fine, but tends to shed a lot of its weight at closer ranges. Pretty much the same goes for the accutip.
Again, there really is no real practical difference in trajectory or energy in the bullets, but there is such a terminal performance difference.
Of course, find a bullet that groups the best in your gun, but make sure that the bullet is designed to perform well on game.
In my 30-06, I use the 165 grain X Bullet, which is overkill on deer, but a good compromise on hogs. It groups 1MOA in my rifle.
Also, why are you hung up on Winchester factory loads? For your purposes, I would seriously look at Federal's 165 grain Nosler Partition. It expands reliably at longer ranges, yet penetrates very well. Again, if this load doesn't group well in your rifle, then find something else, but it has been pretty accurate for a lot of .30-06 shooters that I know.
Zachary