Haven't read through all the responses, but obviously see a lot of repetition in the responses given. Something I haven't scene mentioned is you have to compare the cartridges mentioned in a similar platform as the orginal 30-06 mentioned.
I've got 2 very light 7mm-08's that I really don't find any different to shoot than my 1 1/2-2 lbs heavier 30-06.
I've also got a Winchester 670 .243, that really doesn't fit me well and while I certainly don't mind shooting it, I find my 30-06 and such more pleasant to shoot.