Fly reward out of NRT to ICN in March of next year. Looks like F class is only available if you fly UA metal. Flight is approx. 2.5 hours. My question....is the C class on OZ or NH better then the F class you would receive from UA?
Thanks for helping!

The UA F seat is better for sleeping than the sloping seats in Business and far better than their regional seats. The service on UA is hit and miss (more miss than hit).
For such a short flight i would take anything in F or C which fits my schedule, since you will not be sleeping.

In terms of the seat, UA F is far better than the regional NH and OZ C Class seat. However, the flight is short enough to negate the differences. If UA fits your schedule and you want to try out their F product, then you may give it a try.

UA uses a 777 on this route, so it is old F product as of now, although I personally think it is a pretty good F product with true flat seat (not to the standard of the new suites of course) when not factor in the hit or miss service and C Class meal that they serve you. There is no gurantee that they will retrofit their 777 with the new product when you fly the route. I understand your flight will be a year from now, but given none of the 777 has the new product now flying yet together with UA's pace plus the merger, it is not surprised that UA might not be able to roll out all retrofitted planes by then.

UA has in intercontinental F product competing against a regional C product on NH or OZ. So in terms of hardware UA wins.
In terms of service, NH and OZ blow UA out of the water. Its a short flight so really it doesn't matter so much.

BTW, I find the new UA C to be better than their F.

The meals currently in UA F are not as good as NH or OZ in C. But UA's seats will be better in F no matter which generation you get. And they are far more private. The UA intl First Class lounge is pretty nice, eat what you want there in case what they offer on board has not improved.