Cadunkle, we have two trucks with manuals and both reallly suck at the ramps and for hooking up the trailers. Clutches are fine but for minor adjustments of the vehicles, and auto trans is much easier.
I have no trouble on ramps or hooking up, that's driver issues not vehicle issues. I'd attribute your 291k mile auto trans life to frequent oil changes (20k miles or less) and that it probably has a large cooler.