Check out the Lapua .308 Palma. The company has research that shows the small rifle primer is a big boost to accuracy. I believe the Lapua .308 Palma brass is going for about $79/100. There's a deal! Now, why wouldn't they convert all their brass to small primer (Palma)?
.270 less recoil-sure, you're shooting lighter bullets
Hornady shows only 150 gr max load for .270; 30.06 over 200 gr
Lapua does not even make brass for .270 - that tells you something
every calibre will have it's sweet spot at the max loads-give consideration also to .243-Hornady makes a 105 gr bullet with BC .53 in BTHP match and .50 in hunting round. If that's your sweet spot in need, and it sounds like it might be, go for it. But, you best not go bear hunting with it. Same for .270. Now, 30.06 sweet spot is 225 gr, BC .67 for HPBT match, and 208 gr hunting bullet w/BC .648. Now that's where you start seeing the long range capability of the bigger calibres. .338 is great if you want to throw out 300 grain bullets - I don't - can't bear the cost or recoil. .308 is simply
a reduced case 30.06 so not even in consideration, except for the Palma. My personal usage would be a reduced load in 30.06, using the flat shooting bullets for most use, and a few loaded to MAX just in case a hunting opportunity arises where distance is extreme. But, it's insane to expend a max round on a 100 yard shot at medium game - just gross overkill. I would have light rounds chambered and max rounds in a side pocket for special occasions. A mule dear at 600 yards out can wait for me to change out bullets.