The one suit case rule is in effect. The rules today on flights with them taxing for extra stuff, I feel better off with one check-in and one carry-on. The Airlines today will try and make a buck on the backend of your ticket price and they do have you because 9 times out of 10 you’re at the airport. What are you going to do?
The suit case should have shoulder straps and wheels. The wheels are for those long runs one makes when trying to might the flight on time because of the Bangkok traffic or you woke up late. The wheels are a pain if your destination has no paved roads or walkways and has been raining for two days straight. The shoulder straps come into play when the wheels fail. I’ve had to slip on the luggage and sit on a moto-taxi to get into town.