It’s a great place to enter mainland from Koh Samui. Then travel to Khao Sok National Park. It’s great there.
Surat Thani is not the most beautiful city in Thailand, but it is the main hub to go to the islands on the Gulf: Ko Samui, Ko Phangan. If you need to spend some time around the bus station, go to the lovely August Cafè
Most travellers rush through Surat Thani without stopping, on their way to the islands, but the town gives a rare opportunity to see a busy Thai settlement that doesn’t have a big tourist focus. People in Surat Thani are simply living their ordinary lives, without relying on tourism. It’s also very good value to eat and sleep in this town, so makes a decent stopping off place.
I am writing this about the Airport I used this airport on the way to Koh Samui as it is more expensive to fly to Koh Samui direct and I had plenty time for the catermaran experience however if time is an issue I would spend the extra and fly direct to Koh Samui as the is a lot of downtime.The Airport here is OK to wait around when returning from Koh Samui with variety of food choices and clean bathrooms going the other way is not so good ,the bus trip to the boat was not great and kind of slow and the bus was not well ventilated waiting for the boat also did not have very good facilities .suggestion fly direct.