I am learning to take apart and service movements through an online course. Pretty fun stuff. I started with a swiss 2801 and did an asian 6497. I have a few swiss 6497s. the swiss movement gears are beveled thus making a smoother action with respect to the gears. I can see this adding years of life to the watch. Other parts of the swiss are machined a little better as well.
However, a fully serviced asian keeps excellent time. But, over time the gears, which are almost flat, will tend to wear more and thus potentially fail sooner.
So, if you are buying a watch that you plan to pay a dealer to service buy the swiss. If you are going to do no service and pitch the watch in a few years buy the asian. The asian or swiss could be dry out of the box and need servicing immmediately so that risk is always a factor. Rule of thumb is to set a baseline and service out of the box. that way you know what you have.
You will have difficulty getting parts for an asian vs an eta but this is true only for now. i for one will take parts off another one but I like doing it. I would not pay someone to do so as a new asian movement is less money than a service.
Read Vac's posted in the diy section. He and other members have some fantastic pics of these movements.