Electric fans and A/C

I have not installed electric fans as of yet but am thinking of doing the Contour fans on my Champion rad with a Dakota digital controller.
Most of the setups I see have the fan on while the A/C is working and I get that if you are in town driving. 95% of my driving is on the highway and I would dought the need of the fan being on above 35 mph.
Would I be better off just using the controller to regulate my engine temp and have a override switch that I can turn on in the car or have the switch turn off the fan when I`m at speed on the highway.
What are you guys doing with electric fans and A/C
Thanks Mike