I was working in a luxury watch store back in 1994, the store carried Franck Muller watches.
I can attest to the fact that FM wacthes are inferior in quality back then. A customer bought a cintre curvex model that had the rotor rubbing against the case, the watchmaker opened it to see major metal shavings inside. We also had other issues with the jump hour, and numerous problems.
That was then.
I don't know about FM watches now, I guess, if you are buying one with esoteric movements by Renauld (spelling?) & Papi, then you are getting a work of art. Otherwise, I'd stay away from the usual Casablancas or time-only watches, you never know...