I like that you have access to all of your information in one place, so it is easier for me as my manager/supervisor than having multiple different sources with conflicting info about when someone's available or not! Also very easy set up process - just click "add" button at top right corner once logged into site- no problems there either (at least compared w other sites).
There really isn't anything bad i dislike yet but maybe if we do change jobs after using this tool then switching will be difficult because everything would need changing again!! It was nice being able get instant updates from our team members regarding availability etc without needing them individually emailing us each time something changed which could easily go missing amongst many emails coming across daily anyway :).