Thanks for the kind words, gents. The 15400 is such a photogenic watch! Easy to capture it's good side in pics!
As for which I would choose; having both JFv5 and ZF side by side, I would pick the ZF every time. Great finish and detail, beautiful dial, nice slim profile, and the bracelet has links that move freely and conform to the wrist much better without binding up or feeling stiff. The JF feels like a rigid cuff around the wrist (always reminding me of it's presence) whereas the ZF feels very natural and comfortable.
The thinner caseback also makes a difference in how the watch sits on the wrist as well; the JF feels pretty bulky with that thick caseback.
Yeah, I'm still in the honeymoon phase with this watch, but there isn't really anything not to appreciate about this watch. The Royal Oak has always been one of those designs that I've had a love/hate feeling for; love how it looks, but never enjoyed how they fit my wrist (especially the older variations with the single fold clasp). The ZF 15400 is the first one I've been able to wear *and* enjoy without wanting to take it off after an hour. In fact, it really hasn't left my wrist since I rec'd it yesterday afternoon (aside from a brief few moments to take pics). And yeah... I showered with it on, too. No issues there with water resistance either.
I originally had an order in for a black dial noob 116500 with thin subdial rings, but ended up changing my order to the ZF 15400 after it was released. And I'm so glad I did