IMO, Wby. blew the 338-06 deal by not offering it in a Vanguard, & having affordable ammo available. It is a great cartridge, but was just too costly for the potential market- just my 2 cents.
As far as the 6.5 goes; I love them all. The available bullets are superior to 25 caliber offerings, & 6.5's of any genre seem to be inherently accurate, unlike the vast array of 7mm"s in the marketplace. It's not muzzle velocity that makes a 6.5 so effective, it's the fact that it retains so much of it at extreme range. Anybody who owns a .264 Win. Mag. can attest to what I've said.
Now, if I could just get Wby. to offer a 6.5/300 Wby. It couldn't get any better, in my mind.
Jim