I like that it has many features to help with my calculations which is exactly what i need for work! Also, being able fix problems as they arise or come up in other applications makes this very helpful too!! Nothing really at all but there are some functions missing from calcmaster (for example, an equation editor) so sometimes you have to use another application instead. However, once again - nothing specific here either just more of these little annoyances when using any program/application compared to others out their though maybe due to how much time we spend working?