Well MM,
I'll just make a gentleman's bet with you that the 35 BW has more case capacity that the 358 Hawk. If you compare them, I believe the shoulder is moved further forward and is a sharper angle on the BW. Be happy to mail you or Fred a fired case to compare. I would add that the velocities I achieved in 24' barrel were quite similar to what the Hawk is claiming to get.
All that being said, I kinda like the Hawk case design a little better, with it's more sloped shoulder and longer neck. Nice to have correct headstamped brass available, too.
Steve