I don't own any, but I've shot 240, 257, 300, and 416. 240 is favorite of the bunch, and 257 was a close second. 300 and 416 were both well beyond my comfort zone for recoil.
I've come close to pulling the trigger on a 257 a couple times at LGS, but the price of brass and eating so much powder just put me off. Ended up with a Savage 25-06 instead... total lemon that I traded off within months of buying it. In hindsight, I should have gotten the Vanguard in 257.
In my experience with a couple of 'em, the Vanguard .257 Weatherbys really shoot well. My first .257 Wby. was a Vanguard Sporter, with a walnut stock and blued barrel. It would put three of the handload I worked up (Ramshot Magnum and 100-grain TSXs into 1-1/2"--at 300 yards.
