I think watching the OVAs after you've seen the entire series helps you appreciate them better. It makes them seem more like a reveal of Chise's past in specific more than what they show in the series. You get to see what happened to her between the times that her mother died and before she was bought by Elias. If you watched it without the original series in mind, it may just seem like a little side story. I definitely would recommend rewatching them after the original series.
While it didn't move me to tears, I think that this story was emotional in it's own way. It was very nice to see Chise's relationship with Miura and it was emotional to see what happened with it at the end of the day. I hadn't expected the story to take that kind of turn at the end. Each part of this OVA was beautiful and I enjoyed every part of it and would recommend it to anyone.
