As far as I know, man...the Swede has more case capacity and can outperform a top loaded 260 slightly. North American makers load it weak, same as 8mm Mauser, don't let that tell you what the round can do. The Lapua guys load it like it is meant to be loaded, I think a 123 gran Scenar at 2800 fps.
There's no reason not to use 1:8, that I can think of. It won't bother the lighter bullets any.
The 260 Rem will get you a short action, if that is one of your requirements.
I wouldn't predict there to be much difference in accuracy between the two, if any, but that's just me. Plenty of guys know better :lol: