Vented tailgate

I bought a "V" gate a number of years ago because I figured it wasn't if I was going to hurt my solid gate, but when. With the "V" you don't have to worry about forgetting to put the gate down and back up. As far as mileage, you are pulling a trailer or a FW, forget about getting better mileage. As far as safety from theft, I think a large number of them have keys to lock the gate so it only leaves a small place for those pesky thieves to get in if you have a covered bed, which I don't because I don't normally leave anything in the bed that I don't want to get stolen. But then, that's my personal preference and not everybody has the same preferences.