First off, whoever did the casting did his/her homework properly (presumably read the LNs and watched all four seasons of the anime adaptation); each lead character, while their physique and hairstyle were sometimes a wee different from the original, their voices and characterizations were nevertheless spot-on good or even fabulous (heck, the girl who played Shimako sounded almost like Mamiko Noto, ditto for the actress playing as Sei Satou).
Brilliantly, they also picked the setting and filming location close enough to the original, down to the old-style wooden desks and the (slightly creaking) wood flooring. It gives you the feeling that you're in the real Lillian.
What about story? The film covers only the first volume, but with a few twists in chronology, and what makes this film set apart from the anime adaptation is the greater emphasis on Yumi's adoration of Sachiko, especially that she gets a glimpse right before that fateful meeting. I can't spoil any more but its storyline really hews to the light novel.
Service? As always, don't expect any more skin exposure or the usual items found in similar-looking shows, but there are those funny little moments of "service", especially during the dress rehearsal.
Overall, I can only say that once again the ones who can appreciate the movie in depth are the fans who have enjoyed reading the novels and watching the anime adaptations, basking in the ideal world of the Roses and their special relationships.
I can only rate this flick a 9/10.