760.....Simonis recommends it for straight pool....and so do I.
The straight pool players that favored heavier cloth were usually the ones that didn't want
hundreds being run on them...they were not doing the game a favor.
I even knew one top player who admitted that he preferred loose cloth....
...so even less runs were possible.
You might also consider the speed of your cushions. Slower rubber perhaps the 760 would be better. Speedier cushion would conversely favor 860. This strategy can apply to any game.