Seconding. I've used conduit before, and it was a delight to use something so carefully designed. The blog posts about conduit are in themselves an insight into how to think with Haskell.

http://www.yesodweb.com/blog/2013/10/core-flaw-pipes-conduit http://www.yesodweb.com/blog/2013/10/simpler-conduit-core