Hello,
As of 5 October, I have been using the new NRC app from Nike and also Apple's Workout app on an AppleWatch Series 0, WatchOS 3, iPhone 6S/128/iOS 10. I've been a longtime user of Nike+ and now NRC, especially with the AppleWatch app version of the latter.
NRC on AppleWatch currently is effectively broken, in terms of its ability to responsively display current run stats. Bottom line is: it doesn't. Despite the improvements in responsiveness in WatchOS 3, NRC is (literally) dangerously slow to update (such that a runner must look at the watch for ten seconds or more to get updated, current run stats). Because of this, I have started to run almost exclusively with Apple's much more responsive Workout app.
HOWEVER, I have been impressed with Nike's interaction with me on this topic. I have been in a running (pun intended) exchange with someone in their support chain who appears to be taking my feedback onboard. It is possible that some/most/all of my concerns will be addressed in a soon-to-be-released update.
So, I like NRC for all of the post-run analysis you can do, on the phone and on Nike's web pages; the Workout app has almost nothing to compare to that. By contrast, I like the Workout app for the insanely up-to-the-second updates and responsiveness when you look at the watch. If Nike manages to implement that responsiveness in NRC, I'll be there for the foreseeable future. Until then, I'm 100% on the Workout app.
FWIW, I'm a marathoner, with two coming up between now and December.
Tiger