Pretty darn good
You might ask why get this if you have iCal or google calendar? Well, it is more intuitive for making appointments, as it is focused on free time. I love the summary of free hours , as it allows one to pick a day with lots of availability at a glance. Also, you can see what days you can take it easy or if every spare minute needs to be harnessed.
Ifthisistakenihacetostartover about
Free Time 2: Calendar Availability & Schedule for Today's Meetings, v1.1