Taking this course was an great way to learn more about compilers and fill a hole in my CS curriculum. Professor Alex Aiken is a great instructor and covers a good amount of material. I learned a lot about compiler construction despite having toyed with my own compiler before starting the course. The programming assignments were particularly tough, giving me useful experience in building compilers and a great sense of achievement.
(TL;DR from my full blog post: http://dirkjan.ochtman.nl/writing/2012/07/21/compilers-on-co...)