I have 2 automatic watches, an Invicta Pro Diver and a Parnis GMT. I set and wound both of them and put them on a watch winder. After a week, the Invicta has kept near perfect time. The Parnis started loosing time after a day and eventually stopped. If I were to replace the movement in the Parnis is it difficult or even worth it and do GMT watches require a special movement? Otherwise the Parnis is a great value watch, just a disappointing power reserve.