The ability to see how much time is left in each day, as well seeing if there are any open tasks that need my attention or not! It's also great for keeping track of all appointments I have set up with clients/customers - it makes managing them so easy!! There isn't anything really bad about this software but maybe looking into adding more features would be nice (you could add multiple calendars from different sources).
This has made things easier than ever before when working at an office where we had no way other then our own notes system which was very difficult sometimes using just one screen can make life alot simpler especially since you know exactly what your next task will likely entail.