I use both ScriptTasks and ScriptComponents when I need the power of .NET to achieve a specific function.

ScriptTask - Use the Microsoft.AnalysisServices namespace to dynamically create partitions in SSAS.

ScriptComponent - Time slicing events and optimised aggregations within sorted data flows. The latter being when the input's sort keys match the primary keys in the aggregation. Bespoke code but makes the aggregation block much more memory efficient and semi-synchronous.