After travelling for 4 week from Eastern Crete to Western Crete with a sidestep to South Crete by using both KTEL companies ( https://www.ktelherlas.gr/en/ and http://www.e-ktel.com/en/ ) for the major distances, I can only have positive words for both companies. We experienced big customer care, responsible drivers, friendly staff on and off the bus and in the different bus stations.
And fyi we payed 55 Euro/pp all together for the following trips:
Sitia to Ag. Nikolaos
Georgioupolis to Chania to Paleochora
Paleochora to Kissamos
Kissamos to Chania
Chania to Chania Airport