Thai Airways Royal Orchid Plus - HND to BKK - C or F?

Hello folks..

Presently booked in C HND->BKK->HKT and back.

Considering using NH miles for a *A upgrade to F if available.

Outbound flight departs HND after midnight, early AM arrival into BKK.
Return is a daytime flight.

What're your opinions on the value in upgrading one or both of the long haul legs? Is it worth it? I assume the C seats are still angled and not lie flat.

Thanks..

Is it the 77W?

Those C seats are flat in a herringbone configuration. The F suits are completely flat too. Personally I would go for the upgrade.