Thoughts on hood louvers?

Is anyone here running hood louvers? I'm looking into them not for the ascetics, but to reduce under hood heat temps during low speed rock crawling. Any thoughts or input? I'm thinking of getting these or something similar.

 

I would hate to cut into a hood and then hate the look of the louvers, there is no turning back. Go find a tacoma at an auto salvage yard and do your louver mod on wrecked tacoma hood you buy for cheap. When it's time to wheel, swap hoods. Or heck, just take the hood off while wheeling...........

 

It will help some for sure. While it would be more expensive you'd probably be better off with dual fans if you do a lot of crawling?