I'm a automatic fan, but i am really lazy
Those truck 4-speeds are virtuially bullet proof....but it takes forever to shift them. The granny gear is also nice for pulling a massive load.
I say if it already has a 4-spd, leave it alone. 4-spds are cool enough that i wouldn't bother to convert....if it was a 3spd on the collumn i would rip it out though