Review on 20-sim by Adam Tidd

I like that it's easy to use, has an intuitive interface, and can be used in multiple ways. There are some features missing from the free version (such as being able to save data). Also, the price of the premium version seems high for what you get. If you're looking for something with a lot of flexibility, this might not be the best choice. We've been using this product since we were at E3G, and have found that it allows us to simulate many different scenarios without having to constantly switch between programs or worry about losing our work when saving files.