Absolute Anime

I'm getting ready to purchase the first volume of the TV, but I'm wondering a few things. I know that Yomiko won't appear until the 4th volume, and I know that chronologically this takes place about 5 years after the OVA. I'm wondering though, is Yomiko in the TV still the obsessive, ditzy, social klutz that she was in the OVA? Or has she changed monumentally? I heard that she's much more sullen and downtrodden in the TV than in the OVA.

Well?

Then I won't be spoiling too much by saying that you're not far off the mark.

her voiceover was different!^^

You're pretty much correct. Although the situation between the two (OVA/TV) is different so it does fit