A6o is superior to 64o in any way and is not even close.
A6o vs 64o
Equity Win Tie
72.05% 70.66% 1.39% { A6o }
27.95% 26.56% 1.39% { 64o }
A6o vs random
Equity Win Tie
57.68% 55.87% 1.81% { A6o }
42.32% 40.51% 1.81% { random }
64o vs random
Equity Win Tie
38.01% 35.00% 3.01% { 64o }
61.99% 58.98% 3.01% { random }
A6o vs a regy range (20%)
Equity Win Tie
43.48% 41.81% 1.68% { A6o }
56.52% 54.84% 1.68% { 22+, ATs+, A5s-A2s, K8s+, Q9s+, JTs, T8s, 86s, ATo+, KTo+, QTo+, JTo }
64o vs a regy range (20%)
Equity Win Tie
32.00% 31.46% 0.53% { 64o }
68.00% 67.47% 0.53% { 22+, ATs+, A5s-A2s, K8s+, Q9s+, JTs, T8s, 86s, ATo+, KTo+, QTo+, JTo }
A6o vs a fishy range (40%)
Equity Win Tie
48.39% 44.44% 3.95% { A6o }
51.61% 47.65% 3.95% { 22+, A2s+, K2s+, Q7s+, J8s+, T8s+, 98s, 86s, A2o+, K8o+, Q8o+, J8o+, T8o+, 98o }
64o vs a fishy range (40%)
Equity Win Tie
33.69% 33.13% 0.57% { 64o }
66.31% 65.74% 0.57% { 22+, A2s+, K2s+, Q7s+, J8s+, T8s+, 98s, 86s, A2o+, K8o+, Q8o+, J8o+, T8o+, 98o }
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Even if you gii vs someone who only gii TT+/AK both are shitty but still A6o is better.
A6o vs TT+/AK
Equity Win Tie
25.78% 24.97% 0.81% { A6o }
74.22% 73.41% 0.81% { TT+, AKs, AKo }
64o vs TT+/AK
Equity Win Tie
23.51% 23.29% 0.22% { 64o }
76.49% 76.27% 0.22% { TT+, AKs, AKo }
So meh, don't play both but if have to chose go with A6o