[Note: I also attended the workshop and am writing this before reading the main post to avoid being biased.]

The out of class discussions alone were more than worth my while. However this is partially due to my circumstances, I am about to graduate college with a double major in CS and psychology. Deciding which (if either) field to pursue, and how to best pursue it is obviously quite important to me. Before going to the workshop, I had already done most of the obvious “due diligence” research on the matter, but still updated significantly during the workshop. Talking to several of the other CfAR participants, the instructors, and several LW people who stopped by (Lukeprog, Yvain ect.) uncovered many important points that I had missed. For example, I assumed the median staring salary for computer scientists was a reasonable estimate for what my starting salary would be. It turns out that I can expect to make about twice that much money if I use certain job hunting techniques I learned at the workshop and optimize for money (instead of, say, cool sounding problems). I don't expect most people to be in similar positions, but I do think asking questions at a CfAR event is a very powerful way of researching a fairly large class of problems. If all else fails pick one position and offer ridiculous side-bet odds with a high burden of proof on the other person.

As for the official lessons, if I actually internalize them all, and they work as advertised they will be some of the most important things I have learned in my life. If we take the outside view and assume that I will retain and successfully use them at the same rate as skills I learned at similar retreats then the expected value drops by more than half, but is still pretty high. Furthermore, I have several strong inside view reasons to believe I will retain more of what I learned here. The most obvious is the six weeks of follow up, but there are other reasons, like the fact that I actually slept at CfAR which should increase my retention.

-Edit, minor gramar stuff fixed. Also, I endorse the OP's view of the workshop, except for the sleep part. In particular I forgot to mention the venue, but both the Rose Garden Inn and the food were both spectacular (this was despite my having dietary restrictions). One minor complaint, the Inn could use more writing/setting food down surfaces.

In conclusion tell CfAR “Shut up and take my money.” or you will not go to space today.