My results are a little different.
I get:
(1 == 1) && (1 == 1) command no bracket in 1157
1 == 1 && 1 == 1 command no bracket in 1093
(1 == 1) && (1 == 1) command no bracket in 1079
(1) && (1) { commands } in 953
(1) && (1) commands in 875
(1 && 1 || 2 == 3) { commands } in 1093
1 == 1 && 1 == 1 { commands } in 1219
(1 == 1 && 1 == 1) { commands } in 1235
which means
(condition) && (conditions) commands is faster for me, but not for you. Am I missing something?