I really don't know what I'd choose if I were flying blind. I shoot a 270Win because dad shot one. I could shoot the .270 for free, if I chose something else, I'd have to buy my own components. Even by Jr High I realized that more shooting for less $$ was a wise move. I have since deviated from dad's old standby of Win 760 powder and a 130gn Sierra Game King boat-tail to using Ramshot Hunter and a 140gn TSX.
The next logical step for me was 300Win Mag because again, dad had one, as did a good share of the others that I hunt with. I worked up my own loads, but, even that was mostly plagiarized from friends.
I've killed 2 elk w/my 270Win. 1 w/140TSX, 1 with 150gn ABLR. 1 W/257Wby/100TSX, 10 with 300Win Mag and 200 Partition (x2) or 200TSX (x8). Sat right next to my cousin when he killed an elk w/my 270Win/140TSX combo and right next to a friend when he used the same 140Gn TSX load through his own 270Win.
The 300Win hits a LOT harder than the 270Win. The reaction to being hit with the 300 is significantly greater than what the 270Win delivers. That said, I've never had a rodeo with an elk shot with a 270Win and I've created 2 of them myself when shooting the 300Win with poorly placed 1st shots. Cousin and buddy both killed their elk with little fanfare as well. Punch the lungs, watch them stand and leak out. All that said, I still reach for the 300Win 1st when it's time to hunt elk.