The comments that come after mine won't be as nice. Why? Because there are two threads regarding this topic, both of which contain the information you seek and then some.
However, I feel that you should get at least some kind of answer.
So far no one has the ZF 15202 in hand yet, only QC photos. However, we can make a judgement based on the QC photos we've seen thus far + the track record ZF has with their 15400 and 15500 release. Both of which were highly praised.
The glaring issue with the ZF at the moment is the fat hand pinon. We'll need to wait and see until someone receives their watch in order to determine whether the hand pinon can be shaved, or whether it was done on purpose in order to hide a larger hole in the centre of the dial.
ZF flaws:
- Hand pinon
- Bezel screws (If you're very picky)
- Thickness (slightly thicker than the XF I believe)
XF flaws:
- Dial tappisserie
- Hand pinon (Not as bad as ZF but still fatter than gen)
- Mismatched lume
Flaws on both
- Movement (or lack of movement decoration)
- Dial colour
Personally, I think ZF is the better rep out of the box. I won't speak about which is closer to gen because the audience here on RWI seem to be split down the middle in regards to this. Hope this information helps you make a decision.