Bad Experience
We bought a flight from Shainghai to Chiang Mai with Spring Airlines. Unfortunately, when we wanted to board our first flight to China from Europe we realized we didn't have any confirmation of the Spring flight from China at all (no email, no sms, nothing to proove that we have this flight booked) even though we got charged. We had to buy another flight from China just to show that we will stay in China only for 5 days and almost missed our flight to China.