I have 280 AI which I used for my first bull elk in CO from 350 yards with 162 gain ELDX - took two steps. Just built a 300 win, with 1:9 twist 24” barrel - looking forward to trying it out with some heavier bullets this summer ahead of another trip to CO!
I’ve only borrowed a friends non-Ti Backcountry but it shoots very similar to my 280ai Kimber MA which I love and have had no problems with. Both seem like great choices although I do prefer the 280ai over 6.5RPM