I was also surprised about the detailed feedback. I was not expecting that. It was too superficial to help you to improve. I can say that I interviewed for Microsoft Dublin.
I have also felt the hurt of rejection..
I got in a few stages at Google, got dumped.
I made it to a final interview at Apple, and they bailed.
Applied to Pixar, Mozilla, 10gen, twitter, etc... also with little to no word back at all.
Honestly I feel like the #1 thing I learned from my job search is that the interviewer you get has a insane impact on the outcome. This is especially true of technical phone interviews, I felt like I was literally unable to communicate with some of the interviewers at google because of a language barrier. The whole process seems heavily based on luck.