I spent some time programming with Max (less with MSP) and found roughly the results that others have reported for visual languages. It makes something like an FM synthesizer (y = a sin(b sin (ct))) look a lot more pleasant to a non-programmer musician, but for bigger projects it slows you down and gets in the way and prevents version control etc. But I didn't spend a lot of time with it, so a grain of salt is needed of course.