Land Rovers have been so pervasive in Africa over the last 20 or 30 years that finding desperately needed spare parts on old broken-down Landy is very likely - even in the remotest of African villages. The same cannot be said for modern, albeit awesome, 4x4s. What that says for the Land Rover's durability is an arguing point that my Toyota friends would certainly pose, but in reality it's true, any vehicle is prone to failing at some point and it's undeniable that having a ready supply of old parts is always super-useful.
That said, I'd probably rather road-trip though Africa in a comfy new 4x4 and fork out the money for a satellite phone than take a 4,000km trip in one of these rattle-traps. :)