I have owned two Land Cruisers and Six Defenders. They are very different beasts. I have traveled in deep desert with Land Cruisers and Defenders, and they are both great vehicles offroad. Modifying them for expeditionary travel is vastly different between the Land Cruisers and Defenders. The Land Cruisers have different body styling and their suspension varies widely according to what country you are in. The torque curves on the engines are very different as well. My six Defenders were nearly the same wherever I have been in the world, except that three were gas and three have the 300 tdi. Setting up the Defenders for expeditionary travel was easy after I did it on the first one.
For expeditionary travel, I prefer the ruggedness of the Defender. It is a very forgiving vehicle, and fairly easy to work on. A rest of the world Defender with a 300 tdi is a workhorse that can take you anywhere on the planet (I only visit warm places). A Land Cruiser can be set up to do the same thing. Since I have kitted out six Defenders and only 2 Land Cruisers, I am more comfortable with my Defenders. That doesn't mean the Defenders are better. I just understand the vehicle and it's capabilities better than I do my Land Cruisers.
When I drive around the world, I want to do it in a Defender.