I have to disagree with jmr40 about the power difference between the 30-06 and the 35 Whelen.
Checking Hodgdon's Reloading Data Center, both cartridges in a 24" barrel, we see top velocities of:
30-06 Spfd. --- 200 gr bullet --- 2586 fps --- 49,300 CUP
35 Whelen ---- 200 gr bullet --- 2807 fps --- 49,000 CUP
35 Whelen ---- 250 gr bullet --- 2503 fps --- 48,900 CUP
Cut those barrels back to 22" and the Whelen would fare even better, as it has a better expansion ratio than the smaller caliber. But, I'd say 220 fps or nearly the same velocity with a larger and 50 gr heavier bullet is considerably more powerful.
#1 you are looking at some pretty anemic loads. I show several 30-06, 200 gr loads @ just a hair under 2700 fps. but even at the velocities you list the performance is irrelevent.
Velocity, ft. lbs, bullet diameter and bullet weight don't kill stuff. While it is easy to point to paper ballistics in the end the only things that matter are bullet placement, bullet construction, bullet penetration, and bullet expansion. Paper ballistics don't predict that nearly as well. With the newer hi-tech bullets, or even the older Nosler Partitions in a 180-200 gr. a 30-06 you will get BETTER Penetration than a 250 gr 35 Whelen or 338-06. Stuff falls just as dead.
A lot of guys claim to like the 35 Whelen because they are anti-magnum. Magnum is just a word that was never hung on the 35 Whelen, but you are getting magnum recoil out of both the 35 Whelen and the 338-06, without the magnum performance. I've owned both, and run the numbers on recoil calculator programs. Loaded with 225 gr. bullets or heavier they recoil worse than my 300 mag. If I'm getting the same recoil, I'd rather have a quality 200 gr. .30 bullet, with better SD, moving at 2900 fps. If you load the lighter 200 gr bullets into the 338-06 or 35 Whelen you only have a very, very slight ft. lb. advantage over a 30-06 at the muzzle, but the 180 gr 30-06 is beating it at less than 100 yards if you want to use that as a measure.
Don't get me wrong, I like both the 35 Whelen and the 338-06. I sold the 35 Whelen and kept the 338-06 simply because I liked the rifle it was in better. I enjoy hunting with it, but don't kid myself about its ability to do anything any better that the 30-06. Buying and using a rifle simply because you like it is reason enough. Some guys want to split hairs trying to justify their decision with facts that are irrelevent.