I have 760 on my GCIII and all I play is straight pool. The reason I chose the 760 is because although it is in my basement with a dehumidifier in the summer time, I felt that the 760 in an unairconditioned space would play closer to 860 in an air conditioned pool room. ( Of course I also assumed most pool rooms used the 860)
That being said, I do find it easier to play tight position when the CB is in the center of opened balls and I'm working around close quarters with the 860.
I'm more confident that I'm not going to get an extra rotation on the CB unexpectedly. The same holds true on shots like a hanging OB in an upper corner pocket where the CB has to travel up stream and back down stream after pocketing that ball. I feel I have more control over those last few rotations of the CB with the 860.
Ideally I would like a cloth faster than 860 but a tad slower than my 760. Fussy ba%$@d I know ...
I've read that the 860HR is faster than standard 860, but I don't know if it is really true, if it really says faster as it wears and how much faster it actually is than the 860.
I suppose, all in all, and with the fact that I do enjoy certain characteristics of the 860 for 14.1, without the benefit of actually playing on the HR, I'd have to opt for the 760 again when my table needs to be redone simply because it's too costly to experiment.