If United's aircraft has Polaris seats, then I'd give a slight edge to UA in that department. Although, both are all aisle 1-2-1 seating. If it's not Polaris, then it's 2-2-2 seating and I'd recommend against it, especially given that we're still living in COVID times.

Service and meal wise, there's no comparison. UA is dreadful, particularly as a result of their scaled back meal quality after the pandemic hit. Even if you take ANA's redeye flight (with reduced service, including meals which is a "light supper"), it's still far superior. ANA's lavs are always spotlessly clean (the FAs actually clean them frequently), and they're far more graceful and show finesse in a way that no U.S.-based carrier can compete with.

Entertainment wise - if you want to enjoy Japanese movies, then ANA has a better selection. But UA isn't too shabby in that department, and in terms of Hollywood flicks they definitely have the edge.