I have a 66" twist in my .69. It is shooting into about 2" at100 meters with 85gr. 2F, and one-holing for 5 shots at 50 meters. If one wants tighter groups at 100 meters, one can simply add more powder. It will hold that accuracy with up to 200gr. 2F in the 66" twist but I had settled on 165gr. as being best, just as accurate as 200gr., but delivering the trajectory I was after, at 1,550fps.
I have had 3 .58's. They had 48" twist in the Enfield which shot well with 85gr. 2F, 72" twist in a Zouave, which shot best with 120gr. 2F and a 66" twist Large Barrel that shot best with 140gr. 2F.
So- each is unto their own, but the trend is slower twist, more powder - I would choose a 60" to 66" and be happy. If I didn't want to do any long range shooting, ie: 200 meters or further, I would
opt for the 48" twist & be happy about being able to use less powder for equal accuracy, out to 100 meters or so.