Hi, Just wondering what experiences anyone has had with using these bags on the return trip. Last trip saw a few people with them at the airport. Thought the weight even with one bag inside the other would be nowhere near the weight of a suitcase. Just trying to maximise the 20kg limit. Got slugged $180 excess last time and not going to happen again. Any other suggestions for light bags? Also is there a limit on how many bags in the 20kg limit? Thanks.