It's simple. A well serviced and adjusted movement wins it every time from a non-serviced one. No matter if it's Asian, Russian, German etc.
I serviced a lot of movements over the years and here is my opinion. The ETA clones are on par in many aspects with the Swiss version. Sure some finishing is less and it is harder to work on and adjust for a watchmaker but in terms of reliability imo they are the same: the design is the exact same. A non-serviced and dirty Swiss movement is as unreliable as an Asian clone. And that is the problem with our reps. It is a role of the dice because you never know, Swiss or Asian, if you get a clean and well oiled movement. Sometimes you do, but most of the time you don't. Especially when you choose a Swiss ETA version because big chance you get an old stock. The clones are all brand new movements.
PS: All movement services performed by dealers are highly questionable. They often cut corners to make an extra buck. You're better off buying a rep with a movement of your choice and have it serviced by a trained watchmaker with credentials you can look up. There are some on the different fora.