technically NH803 is operated by Air Japan, NH801 is operated directly by ANA
they may have a minute different if accrualing to a different FF program
plane/service/food is the same as mainline ANA. difference is typically staffing, though they should get the same training (~foreign-based for different tax structure)
787-10 is brand new.... if that's your thing, go for it
https://www.ana.co.jp/group/en/pr/201904/20190405.html
"The 787-10 is a cutting-edge plane and ANA is honored to be the first Japanese airline to fly the aircraft,"
The Boeing 787-10 is scheduled to begin flying on April 26, 2019, from Tokyo-Narita to Changi-Singapore before it begins service from Narita Airport to Bangkok's Suvarnabhumi Airport on July 1, 2019.