Okay, okay. The movement's quality. Obviously, there are going to be better quality movements than others. I have read a lot but nothing specific saying this movement is better than that movement. There can't be THAT many movements in our Rep category.
It can be a rough audience sometimes mate . . .
They do have a point tho, it's not really quantifiable in the way you want. Not all movement are created equal and not all MVTs can be used in all watches and there are dozens and dozens of MVTs made by many mamkers. A 21J by (for example) Sea-Gull is a simple yet robust MVT yet the same MVT by a lessor maker may be a POS.
Obviously at the top sit actual Swiss MVTs by ETA and Selitta but very few stock reps will have them installed as a simple 2836 from either is well over 100 bucks wholesale tray price and a 7750 starts at 300 or so for a low grade. The next tier are the quality Chinese ETA clones from makers such as Sea-Gull. PTS Resources or Tianjin Watch Factory as well as the venerable ST-19 and a couple of the tourbillons from Sea-Gull and PTS. At the same time there are many far less reliable clones from lessor makers and some very bad tourbies out there and it is impossible to know what's in your watch, you just need to trust the maker to use reasonable quality MVTs from decent makers. Hovering around this same level are a couple of Japanese MVTs such as the Miyota 9015 (a constantly debatable MVT if ever there was one).
Once upon a time the Chinese 7750 clones were utter crap and about as reliable as the proverbial two bob watch but those days have changed. Yes, a lot still come dry or close to it but given a service (and preferably a gen mainspring) they will last as long as the real deal Swiss as long as the correct care and feeding advice is taken. Even if left dry for an avid collector little issues will develop for years as you aren't wearing it every day. Some of my 7750s are serviced, some are not. The main issue with 7750s is when they get modified to allow for seconds at 3, 6 or 12 instead of the native sec@9 layout, it's added gears that cause issues. Even these are better than they were (10 years ago they were a total timebomb) but can still give issues and definitely benefit from a service of they are to worn regularly. The main issue with any 7750 is folk who don't obey the care and feeding rules, don't run the chrono without a good power reserve, don't set the date unless the time is set between 4 and 6 first and don't reset the chrono with the seconds hand more than 5 sec from 12 if you can help it.
The other chrono is the venerable ST-19, the best of these is the Sea-Gull, this movement is a bloody good MVT and if looked after is bombproof. It is a better chrono than some Swiss examples if the truth be known. In its native form as a two register (subdial) MVT it will outlast you if cared for correctly.
We also have the many variants from many makers of the hand wind MVT used in the majority of PAMs, most of these are solid as a rock.
We also have the various Rolex "clones" )I use inverted commas as none are true clones) most if not all of which I would not touch with a ten foot barge pole. What the heck is the point of using a fragile, unreliable MVT that wouldn't fool anyone who knows what the real deal looks like especially in a closed caseback watch such as almost every Rolex? This also applies to the CHS (Correct Hand Stack) "clone" GMT MVTs, no one will see the order of the hands on your wrist and 99.98% of people would not know anyway. Hell, most owners of gen GMT Rolex would not be able to tell you the stack order without looking at theirs.
Then we have the rest, mostly the 21J AKA the China Standard Movement. The quality of these can range from "hand it down to your son to give to his son" to "how the hell is this running at all?" Once again you rely on the maker to use a decent example but these are used less and less now as the China clone ETA is replacing almost all of them in decent reps.
And that, in a nutshell, is about it. About 20 movements from a dozen or so makers resulting in 100s of variants depending on what its going in.