Any mechanical movement can be reliable if it has been serviced properly. But the converse is just as true.
The movements in nearly all rep watches -- regardless of whether they are gen ETA, Asian-made ETA clones or cheap/generic Asian -- are either used or unserviced. This means that, at best, you do no know the condition of the movement &, at worst, you have a ticking time-bomb that is not likely to last very long. For this reason, it is generally recommended that, for any good watch -- rep or gen -- you need to rely on or plan to keep, you have it professionally overhauled upon receipt. Then, like all mechanicals, you should expect 5-7 years of trouble-free service until the next overhaul. Of course, it does not pay to service a $100 watch powered by a generic Asian movement.