I have too be fairly honest Konata made the entire series watchable, I don't think I would have watched it without her. I think this series got popular quickly because of that reason, but it's worth a watch it's not the greatest comedy out there, but there are some pretty funny moments.
It started off great, but the ending was a disappointment too me. Overall, it's watchable for a first time, but for me I don't think I'd re watch it much at all. The series was funny, and that's what kept it enjoyable.