There are several great lessons and a ton of wisdom coming from these two men. They really employ logic to what they do. Some of the lessons:
The main lesson I take from this is that Warren must be really good at evaluating people he wants to partner with. This man leads one of the largest conglomerates in the world and reads 5 hours per day and has 22 people at his corporate office. Clearly he knows how to evaluate good businesses and delegate.
What makes them unique is that they do NOT buy businesses and try to integrate them to their main business or paste them all together. I really believe that working all of these years to your strengths minimizes stress and is one reason these guys are still doing it.
Work in a field that promotes your strengths