Whatever else you take away from SERE, the most important thing to remember is to make sound decisions using what you have been taught. In other words, make sure you don't do anything stupid that will kill you or make others have to care for you.

As for the SAS, I have had the pleasure of working and training with them in my mispent youth. They are well organized, have strong tactics and are extremely physically fit. The ones I have met were excellent marksmen as well. Their training didn't focus on survival as much as American troops. I think this has more to do with the availability of varied terrain that we have in our country than anything else. We can train guys in the desert, jungle, forest, swamp, or mountains without ever leaving home. Also, from hanging out with them off-duty, I think they must have to fail some type of psych screening to qualify for training, they did things for kicks that were downright stupid.