Well these two ova were fun to watch and the enjoyment is guaranteed.
The first ova is your typical hot springs trip, where a lot of misunderstandings happen. Beside the top notch fanservice our characters also have a little cooking contest where Erina fulfills her duty as the God Tongue . The comedy is also good i found myself laughing at the end of it so it's worth a watch.
The second ova is really a must watch because it's the premise before season 3 and it will help you understand what happened if you haven't read the manga. It focuses on the introduction of the
Elite Ten and the start of the Moon Festival. Despite creating a little tensioned atmosphere between the characters it also doesn't forget its light-hearted comedy to entertain its audience and depict the characters personality traits and quirks.It explains also a lot of stuff about Elite Ten and their influence in Totsuki Academy so it's damn interesting and you don't wanna miss that.
Compared to the first OVA which was more or less two side stories that aren't that important these two episodes are in my opinion a must-watch before starting season 3. Not only do they have a lot of character development and foreshadowing (especially the first episode), the second one introduces the Elite Ten in a much more well-paced way. The first episode takes a few scenes from the OVA and doesn't linger too much on it, this OVA goes in much more depth.
Story-wise, as I said, it's an essential watch in order to fully grasp some characters and motivations
(especially Momo-senpai who sadly had 0 character development in the first cour of the third season while in the OVA there are a few scenes where she is more fleshed out).
In the other aspects like art, animation, sound, etc. it's consistent with the second season.
Also, in the second episode the best character in the whole series appears for the first time: Kobayashi Rindou, so that's a 10/10 by itself in my book.