The kind of terrain makes a huge difference...
I've had a few 2x4 trucks, and they're just fine pulling trailers around on the gravel or pavement, but the minute you go off-road with a trailer and have to make a tight turn or back up to a coral, it's all over. We have nothing but red clay dirt here, and when there is any kind of ground moisture it turns into quicksand..
The most important part though, is driving down hill, with or without a load, if you don't have 4x4 you'll be going for a ride down the hill...been there too many times..lol..
I realize everybody has different needs for their trucks, but since I use mine every day (including the winter) and spend just as much time off road as on, I couldn't be without 4x4..
Also the low range is invaluable to me, for what I do..
Rock