Ayende has been very vocal about his opinion of SSIS (SQL Server Integration Services) in the past, and, to be fair, he has some good points and indeed working with SSIS can be a pain in the neck many times. However, I've discovered that I despise SQL Server Reporting Services (SSRS) far more than I could ever SSIS.
Working with Reporting Services is about as much fun as sticking needles under your fingernails. It insists on changing stuff on it's own, like switching report parameters to multi-value after you tell it you want them single-values, reverting a dataset parameter to some weird incorrect value you once typed in (no matter how many times you change it), or just throwing weird errors in your face. And don't even get me started on the joke that is the MDX query designer.
FWIW, I think most of my issues (if not all of them) with SSRS are directly related to the design-time support for authoring reports; I don't think I have many problems with the actual runtime behavior of it (for now).