In October we have a flight from Izmir at noon the day after the RS tour ends. We'd like opinions on staying the extra night in Kusadasi and taking private transport to Izmir airport early the next morning. OR taking the RS bus to Izmir airport, finding a hotel, and something to do/see that day and evening? If staying in Izmir is better, then any suggestions for picking a hotel at the airport versus in town would be appreciated. Thank you!
If your tour does not go to Sirince, you could consider night there and then transfer to the airport....(??)
Many questions on this topic over the years https://search.ricksteves.com/?query=kusadasi+or+izmir&button=
No one choice better than the other, definitely up to you and your interests. I personally scheduled an afternoon flight from Izmir the day the tour ended. I had a leisurely breakfast and walk around town, hired a Welcome Pickups shuttle to take me to the Izmir airport for my flight. In my group there were people who stayed in Kusadasi, took the ferry to Samos, flew back to Istanbul, or left immediately for home.