Alliant is showing only about 100-150 fps for the Weatherby but doesn't state at what pressure. http://alliantpowder.com/reloaders/...;type=1&powderid=40&cartridge=65

I think the difference is real but would be hard to prove it. The 270 was Ed Weatherby's favorite and he could have anyone he wanted. You can form cases easily from .264 or 7RM if you don't mind them being slightly short or with two passes and a trim from 300 WM brass. The 270 Bee would be ideal for South Texas sendero hunting where you don't have time to range an animal usually. But hard to beat the 270 Winchester so I would go with the Weatherby and handloads if the rangers were longer or the animals were larger.
The Weatherby would instill more confidence on game like Nilgai real or imagined. In my indecisiveness I went 270 WSM and split the difference.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli