The .35 Remington is a mild cartridge, comperable to the 30-30 on paper. The larger heavier bullets give it an advantage with penatration. 220gr is about it's limit on bullet weight, and trojectory is poor. 150 yards is about it's limit.
The .35 Whelen is a lot faster and far more powerful round. It uses the same .358 dia. bullet, but can utilize up to the 250gr bullet. It can be down loaded to .35 Remington ballistics, or upped to comperable ballistics with .338 Win Mag factory loads. While it is not a 300 or 400 yard gun, I have used it at 250 yards with very good results. I load 158gr pistol bullets for plinking, and small game. 180 grain for Caribou, and 250grain for Moose. It is a very versital cartridge. My dad loved my .35 Whelen Handi so much he commendeered it for deer hunting in Tennessee. Dad used my .35 Handi to kill a nice Moose a few years back, recoil was so low with factory ammo, he does not want to shoot anything else.