I use my truck for towing a racecar and
part time commuting.
If you have heavy towing (I tow about
two tons) don't bother with a six cylinder.
Even if you think you might someday want
to use your truck for "real work", get a V8!
It cruises quite comfortably and quietly
at extralegal speeds while not towing
and the "pickup" is good.
It even has very little trouble towing
up steep California hills.
It's too major faults is that the two
rear seats aren't really useful, and the
range isn't great (I get ~12mpg towing
with a tank capacity of somewhat less
than 30 gallons).