I did time in an Artillery regiment equipped with Champs.
The best fun of all was driving in a convoy of 10 or more through a town, everyone in the lowest gear possible. The banshee wail of the vehicles, created by the necessarily huge cooling fan, magnified and echoing in the narrow streets, was one of the "sounds of the '60s".
What was not so much fun was waiting for the specially trained mechanic with a special tool kit, to open up the engine water-proofing casing and change a plug.