[blikdak]

Organization of code seems to be an issue - with OOP it's part of the methodology and design process, code and data goes together into this named class which goes into a file and does what it's called. In FP there isn't an obvious way to seperate out your concerns while making it easy to find and maintain code. Once IDE's, annotations etc catch up this will be less of an issue, but for now I'm tending towards a hybrid approach of classes which operate mostly immutably except for where persistence of state is required, ie very little other state than that which eg mapped to a database.