We have used Hitachi 1.1T windows ACs in our bedrooms. It has now been 16 years and we have now replaced one of them with another Hitachi windows. To say the least, the experience with using Hitachi was very satisfactory.
Apart from regular AMC, the only other cost was changing gas twice in one of the ACs which, over a 16 year period is reasonable. We did not use Hitachi for AMC because it was expensive. We also have a Samsung 1.5T windows in the hall so we get all three serviced by a local mechanic.