as the above have said, there are various flaws you'll have to live with. The next thing is, everybody has their own pet peeves when it comes to flaws/details - and know that 99.999% of the population will have no clue what rehault, crystal height, SEL-Fit, CG, and the like mean
my personal pet peeve: bad SEL fitment, badly shaped CG's
do not care: crystal height above bezel, inlay font for 5-digit references
you see, people (including myself) start nitpicking and obsessing over details that "a normal person" will never notice.
Currently I'm really enjoying my new GMT-IIc with correct hand stack, incredibly well built, new PVD/DLC bezel coating like the gen - but it's off. Compared it to a gen 116710 and the font is way too dark in low light. Only option? Gen bezel going from 350-600... hope this provided a little insight
If you can live with minor flaws that the "general population" will never notice, buy a noob ceramic rollie. if you want to go further, there are (as stated above) builders like BK and TC who tweak current models or build quite gen-like watches (even these won't be perfect).
And of course there are frankens, you can spend an easy 5 grand on a rolex made from 80-90% original parts including the movement. Is that worth it? Thats for the individual to decide