I'm prone to believe that the .243win is the most efficient whitetail cartridge available - in other words, it's plenty more than enough to be enough. The 7-08 then is just a little more "enough" since it spits bigger pills. It's just right on Muley's and not too much on pronghorn.
Factory ammo supply is good for the 7-08 - even the walmarts around here carry it, and they don't even carry firearms anymore.
For a reloader, there are boatloads of brass and parent brass to be had, and plenty of 7mm pills to choose from for different applications.
If they ever find a cure for magnumitis, I'd probably sell off all of my long actions and just be happy with a few rifles 223rem, 7-08, and 338fed. Thank God Magnumitis is terminal!