It's easy to use and most of the time, it's reliable. I've heard of people having some interesting detours. Some people that I know - one time they were taking a bus to the airport and the driver decided to take a detour to get a coffee without telling the passengers, and everyone was just sitting there on the bus . My friends were nervous they'd miss their flight. The Greeks on the bus weren't bothered and thought it was normal. Personally, I prefer either renting a car and driving myself or taking a taxi.