The movement seems really well made though. Don't see a high failure rate with those as the movement is quite simple and robust. No extravagant complications and the date change looks sturdy enough.
Dangdong movements have proven quite reliable. VS 3135 and 3235 have negligible failure rate having the same date complication. Even the 4130 clone is reliable and that given the much more failure prone chrono complication.
I'd say the current Dangdong clones are on par with the sub 750$ gen watches quality wise. A number of my friends have had issues with Oris, Tissot, U-boat. My gen Mido needed a service covered by the warranty.
The 15500 is a fantastic rep. Just buy it!