Rolex reps seem to have the highest QC applied to them. Never had a problem with a rolex rep of which I own 4. Omega reps are a different story. Of the 6 omega reps I own all have had a problem or 3. Mostly due to crappy bezel inserts misaligned to bezel, crystal not fully pressed, clasp mushroom falls off, bracelet scratched or crap, crown stripped or just wrong, stem too long or short, and bezel problems ( no click, too tight, too loose). The movements are usually reliable unless we are talking about 7750 based reps, of which 100% have been defective and required $150 rebuilds to run correctly. ( I own 5 ).
The best rep I have is a 2836-2 Yachtmaster from Andrew. Waterproof and accurate to a couple seconds a day. It has font issues, but thats really a small problem. It is the one shining gem in my collection. I own 36 watches.
jeff