The best thing about this simulation tool it's that you can use your own models or import other people’s files, so there are not many limitations when using simulators like these ones! I don't really have anything to say because all of them work well but if i had something specific as dislike then maybe its how some tools look in general while others seem very outdated compared with newer versions (like their interface). It could be improved by adding more features such us creating new materials/objects from scratch etc., better tutorials too!! This simulator has helped me understand mechanical processes much easier than before without having any previous experience at least until now.