Manual or auto, which do you prefer?

A lot depends on what you’re doing.
A lot of work in traffic, or motorway work, an auto will be fine.
Lots of reversing on gradients, or quickly changing slopes on hills with some weight on, and you’ll need, at the least, a manual override.
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Autos are getting better, but they are designed for the most common use…
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Want an auto that covers everything? Look at the switchgear on a newer Range-Rover. More than just the Forward/Reverse switch on most trucks.
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Most of my mileage is done on m-way, but most of that is done in top gear. So, an auto makes no advantage. The awkward stuff needs me to override the auto box, so the auto is no real help again.
Heavy traffic is easier in auto. As said it makes it easier to update faceache or brew a tea.