c-fbmi - just a few comments for you as a counterpoint to yours on the 35Whelen - related to hunting NA - not Africa.
I sure don't keep my 35Whelens around for nostalgia's sake - the only reason you suggest justifiable for having one today. Also I wonder if you forget how effective 35s are. Do you remember you once extolled the 350RemMag - even buying a second for your son. To use your own words, it "...KILLS (caps yours) wonderfully out to 300 mtrs and beyond." I agree. So surely what's very good about the 350RemMag must attach also to its long action ballistic twin.
If the 350RemMag deserves to live on with such praise, then the easier to feed 35 Whelen does too. The 06 is a good "do all" choice for big game no doubt. I recommended one to my son last year who doesn't reload. However the poor man's magnum is also a good big game "do all" gun. It still performs at least as good (better IMO) as it did when first developed a 100 years ago - being an improvement on the 30-06 for that purpose. I have killed big game with both - 35s properly loaded generally anchor animals better - IME anyway.
As to versatility of the 30-06 you mention, I can shoot 140s to 310gr in my 35 whelens and send jacketed 225s out at 2700 commonplace - with a 22" tube. Not sure how easy the 06 does this (in response to your thought re 06 220s "at the same velocity").
Respectfully,
Whelen B