No doubt the difference between the 30-06, 280 and 270 is more overplayed then Celine Dion after freaking Titanic came out. Splitting hairs I call the 270 the better choice of the three if all we are hunting is deer, but the difference is so small using what you have confidence in is vastly more important. Splitting hairs even further I would say that the mid ranged 6.5mms and small displacement 7mms ( aka 260 Rem, 6.5x55 SE, 6.5x47 Lapua, 6.5 Creedmore, 7x57 Mauser and the 7mm-08) are better still since they can deliver the same lethal punch well past the range of most hunters to place them accurately in shorter, lighter, lesser recoiling rifles. Of those the Creedmoore seems the most efficient. While this is the current ideal cartridge at the moment there are several ways it can be challenged.
1 If the 243 can start getting some more low drag hunting bullets, we know the 105gr A-Max is a .500 BC if they could build a tougher hunting version of that it would be impressive. Still might not maintain the 1,200fpe at range but it would be darn close.
2 If someone standardized the .25-08 aka 25 Souper, while I don't have published load data to compare the little quarter bore seems like it could run with the best of them. Only downside is high BC bullets (.500+) for .25 calibers are non existent and even .450+ are rare, while if you go one size up the 6.5s tend to be very high almost across the board, even the old 140gr flat base bullets run around .490BC and low drag hunting bullets can go upwards of .600+
3 An even more efficient 6.5mm, it would take some doing but never discount the possibility that someone could improve even on the Creedmoore case.
In years past if you wanted to hit with an authority out to 500 yards you had to start off with a very high powered rifle that made 3,000+ fpe at the muzzle, nowadays with advances in bullet design and construction that is not true anymore, good thing is you don't have to accept the changes, your old 300 Win Mag is just as effective as it has ever been, but for those of us who like 5-6lbs rifles and dislike shoulder surgery we now have some impressive options.