I've driven both Kubelwagen and Jeep extensively and I'd have to say the Jeep was vastly superior off-road as it was designed for it, but this is reflected in how unrefined it is to drive on the road. The Kubelwagen is much nicer to drive on the road, but is poor off-road, I'm sure they were next to useless in Russia, where the Jeep would have handled the conditions with ease. A Jeep will go through mud that a kubelwagen will get stuck in, but a kubelwagen is much better to drive on the road. The jeep will probably be more reliable in the field too as they are very hard to break, as witnessed by how many WWII-era ones are still running. The VW engine in a Kubelwagen is very strong but underpowered for a vehicle of that type. In my opinion the good old British landrover is superior to both (and the first ones had bodies made from the aluminium of downed german bombers).
Intelligence Resembles Insanity only to the stupid.