Mike: I don't think they're any more prone to overheating than any other vehicle--in fact, my opinion is that they're less prone to problems than your average car or truck. You also read a lot of posts on this board about the front axles, trannys, suspensions, etc. It doesn't mean that these are problem-prone areas, but that the members of this board like to keep their trucks in good mechanical condition and are a "bit" more anal about maintaining them. They're also more likely to dig into their trucks to made mods or just to check things out. In doing so, they notice things and discuss them. As a result...lots of questions/tips. A knowledgable owner is better aware and prepared to deal with the potential that something goes wrong and can quickly address it if/when it does.
IMO a properly maintained TLC is not prone to overheating at all. It has a large oil capacity plus a stock oil cooler and large radiator to handle the motor heat. On autos, they come with a tranny cooler from the factory. IMO Toyota shot themselves in the foot when they changed the rad in '95.