Speedminer's objective is especially to ETL external databases into Cache to create a Data Warehouse (although it works well with data already in Cache database), therefore ETL is an important module for us.  If you just need to copy data from external database to Cache once, Cache Management Portal already has the feature to do so, Speedminer ETL will be more for continue update of data loading including incremental update.  Speedminer also support data transformation, data profiling and other features.