Excellent
It was easier than I thought it would be , don’t be put off by the reviews. Yes it’s a 3rd party but your collected by a driver, taken to port, go through security leaving, the boat takes 30mins, when at kos you go through passport control and on way back same, but all together took less than 30mins and you have to go through passport control 4 times ! The drivers are waiting for you when you get back , the boat comes back at 6pm, so I would suggest being at the port in kos approx 30mins before