It is specific to all driving. On and off road you get more usable gears. You want the lowest crawl ratio off road so that the engine has mega power and you don't have to use the clutch.I was curious why was this the case? Why is it the 4.10 ratio is better than the 3.45 ratio in a manual? I am assuming this comment is specific to on-road driving.
On road with the 3.45 gear ratio and the 6mt the Jeep is just geared silly IMO (I have owned both a JLS and JLR). With 3.45 gears plan to use 1-3 in town, 4th on the highway and 5th on the interstate unless your above 80mph then maybe you can use 6th gear. 3.45 gear ratio with 32" tires at 80mph produces 2100rpms. You are just starting to touch the power band of the motor.
With 4.1 gears and 33" tires at 80mph your at 2400rpms which is still the bottom end of the engines peak power.