solid security, one touch out-of-office setting.
if you have calendared a teleconference that requires a sign-in code, good lets you call directly by touching the number in the calendar entry and it will usually dial the code too.
if you use folders for email, good will NOT notify you if you get an email that you use rules to sort into folders.
you cannot change the new email notification sound.
you cannot modify good's autocomplete entries for people you commonly send email to.
the app will sometimes notify you twice for the same email, making you think there was a 2d message. the app sometimes takes a few seconds to show new messages, which can be frustrating.
if you open a calendar event and keep it open after the event ends, you cannot return to the app and have to close & restart it.