Equal parts Heartwarming and Awesome: Corona proves Einhart and Otto right despite her defeat.
It's a minor thing, but in the anime, when Vivio, Rio, and Corona show off their test scores to Nanoha & Fate, Raising Heart floats up and uses its solid-magic 'wings' to pat the girls' heads in congratulations.
Einhart's reasoning behind naming her device Asteon: It was the name Claus and Olivie had chosen for a leopard kit who was stillborn. Also a bit of a Tear Jerker.
Nanoha congratulating an unconcious Vivio after her fight with Miura. Vivio might have lost the fight, but she gave it her all, and to Nanoha, that was more than enough.
Ixpellia fully waking up in Chapter 90 just so she can give Vivio vocal support against her rematch with Miura, and the hug they share after her victory in Chapter 92, especially since Ixpellia could have been asleep long enough to outlive her friends from Sound Stage X.