The tool has many useful features, including ability to create custom components with multiple materials such as glass or plastic that can be used in other simulations like FEA packages (Ansys etc.). Also it supports various file types for importing data from CAD files so you dont have load all your work into memory if its too big - which helps when simulating large systems of devices over long time periods! I dislike some aspects mainly around how often updates are released but this seems more down doenloading/updating code than actual product development itself? Its easy enough using an understanding base model setup once then just updating material properties rather tahn recreating everything each update release; however i cant say there really anything about eCosimp thats bad unless u need certain functionality not available elsewhere eg multi-threading support within same process only one thread allowed at any point during execution).