You have a lot of true and fair arguments, but in my experience gens are as far apart by brand as reps can be from gens.
For example I've had numerous problems with my Panerais. Hands coming off, PVD of questionable quality etc.
On the APs I owned (a rubberclad ROO and a T3), the titanium of the T3 was exceptionally scratch prone and the Chrono in the rubberclad got stuck at some point (the start/stop button just "froze stuck"). It took 6 months and 2500 dollars to fix the Chrono because they needed to fit a new Chrono module.
I know of course that this happens (probably even more so) with reps, but the funny thing is that from my 30 reps, all of them run fine and keep pretty good time.
And speaking of time keeping:
My Oris Williams gen gained 12 secs. a day.
My Urban J