Wow, some pretty strong comments on this show! Honestly, it's not as cheesy as some make out. Sure, it's not Citizen Kane, but for what it is, it's not bad at all.
First, I think the casting was great. I often found it unbelievable in the books that the girls were only in Middle School, considering all the things they were able to do (go to NYC at the drop of a hat, babysit infants, etc), so casting older actresses made the whole thing more plausible. Also, I think the actresses have been unfairly criticized, I think it was the writing that was a bit off, it was geared a little too young to be believable, not the writers fault or the actresses, just how it worked out. Also, those who have commented on the lack of television and film appearances of the actresses post-BSC should be aware that the majority of the performers on this show were from the stage, and many returned there after this series.
The series was much closer to the books than the film was, and the supporting cast did well. As the show progressed, it improved drastically. The performers had gotten the chance to get to know each other and develop a working relationship, and the story lines also began to embrace heavier topics, such as divorce and the destruction of our environment.
Good fun to revisit on rainy Saturdays, and something I will surely share with my own children if I am blessed to have any.