today all the major factories make amazing reps compared to a decade ago. Or even 5 years ago. But here's my thoughts on who's the best.
Luminor non-chrono case (6497 or 7750 based watches): Noob factory is second to none. I have torn down numerous (hundreds) of watches from noob factory and have never been disappointed with the fit or finish inside or out compared to gen. The movements are usually clean and oiled correctly as well.
The added advantage is the ability to swap every single case part with gen parts. You can't do that with any other factory
Luminor Daylight Chrono: noob wins again for the same reasons followed by H factory. H factory is good but does not accept all gen parts.
1950 Submersible cases: im a big fan of V6, but their quality is very inconsistent from batch to batch. Very unfortunate.
1950 44mm: VSF hands down, no comparison. I bought a few of these and really couldn't tell the difference from gen. I don't say that lightly.
1950 47mm: SF would be number one. Much like VSF the quality is 99% gen. They are followed closely by V6 and ZF
In general:
H factory makes decent watches but inaccurate CGs, cases with sharp unsoftened corners, and a strange bezel design kill them for me. I avoid HF when possible.
V6F has made some amazing reps but inconsistent care and quality: dirty movements mysterious changes in part shape and size, purple AR on crystals... I avoid them as well but will occasionally buy a V6 being very picky about QC
ZF is okay, but the weird cannon pinion cap on subs and similar quality issues to V6F cause me to avoid them as well.
You've asked a good question. I hope this helps.