(big snip)
leverfan,
When Roy Weatherby decided to "improve" on the .375 H&H, for instance, there were some trade-offs involved.
I got to ask, What trade-offs? Small groups and tight lines to all. Lawdog

Lawdog-
The Weatherby gained quite a bit of velocity over the parent round, which many consider to be a good thing. I'm not overly impressed by high velocity, but it has some advantages. On the down side, recoil is increased, although there are plenty of ways to deal with recoil, so that's not too bad of a mark against it.
On the flat out bad side, the Weatherby does not cycle and extract as smoothly as the original H&H case, especially in very hot weather. I reload with temperature insensitive powders, but I like every edge I can get when it comes to reliable feeding, especially in hot or dirty conditions (like the sort of conditions one might hunt dangerous game in).
It could very well be that I'm just stuck in an old-fashioned rut, since I'm well aware that Weatherby rifles and rounds can be quite reliable, but like I said, I want all the advantages I can get in terms of reliability, rather than speed. I'm unconvinced that a well placed 300 grain solid at 2550 fps from an H&H will be less effective than a well placed solid at 2700 fps from a 375 Weatherby.
Now, the 378 Weatherby may well have a real advantage in terminal effect, but I'll never know, as I have no plans to abuse my shoulder and ears with that cartridge. It's velocity also exceeds the effective range of many bullets, narrowing choices by quite a bit.
To be honest, I'm prejudiced in favor of cartridges that throw a spitzer bullet between 2500 and 2700 fps, have low peak pressure, and even lower pressure as the bullet exits the muzzle (my choice in lever action cartridges is different, of course). Such rounds are easy to shoot, easy to hit with out to my effective hunting range, non-finicky to load for, and inoffensive to folks sharing the rifle range with me. They also offer all the performance that hunting requires, as long as the bore size and bullet weight match the game being hunted. Bolts never get "sticky" in hot weather, cases last a long time, and life is generally good.