I don't really use the LCCs, so it wouldn't really affect me much if they did move. If I did use them though, I wouldn't want them to move as it would be very inconvenient to travel across town to catch a connecting flight. If they moved, it would mean less traffic at Suvarnabhumi, which would be a positive point. But it might mean slightly fewer passengers flying on the remaining non-LCCs, owing to not being able to easily transit from LCC to non-LCC, which would be a negative as more passengers mean more competition which should equal lower prices. I think having a LCC terminal at Suvarnabhumi is the best solution, but having them move back to Don Muang would certainly be acceptable, either as a temporary or permanent solution.