It was absolutely great and adorable. I would say it doesn't have as much loli fanservice as you might expect. It's ratio of loli fanservice to loli moe is somewhere between GochiUsa and Dragon Maid.
I'll check out the no-fanservice edit and report back.
Story:
The show is adorable, although a bit formulaic. The first half of the first episode is focused on what led our MC to become a music-obsessed high-school NEET, including subtle encounters with two clearly soon-to-be main characters.
From then on we hit straight into the story arc introducing the loli band, their immediate motivations, and two side characters including the suspicious characters from the first episode.
Then there's a story arc bringing the MC and the other 5 characters together, with a drama arc instead of a concert arc this time. A romance subplot is introduced for the most appropriate character.
The drama overflows into the next 3 episode story arc about introducing 2 new lolis and their tragic backstory, but this time it's a concert arc. The romance subplot becomes a joke harem.
Finally we get a 3 episode battle of the bands arc between the 3 loli band, and the remaining 3 lolis. The newest loli band loses, but there's no sense of closure as they say that it's only the beginning, and the romance subplot fails to even come up.
It's formulaic and arc driven story combined with a huge "read the source material or pray for Season 2 as you buy Japanese Blu-Rays" ending, knocked off a few points for me. But it was a serviceable story with it's heartstring moments. And it was more than enough to bring out the loli moe characters we're all clearly here to see.
Sound:
Sound was great, loved all the rock tracks. A bit lazy with the editing at times, but the soundtrack was phenomenal for a loli-rock band show. The amateur aspects sounded amateur enough to be convincing. I really enjoyed one character's increasingly terrible piano practice.
Art:
The art in this show is good, but I wouldn't say it's fantastic. You can tell it was drawn rather cheaply, but they have great character design so the moe comes through when it needs to. I'd love to see what the blu-ray brings to the table, but I don't want to be put on any more lists.
Characters:
The characters are all adorable and all get sufficiently enough backstory and explanation to make them believable. Which is a pretty high bar in CGDCT territory. Obviously, not as much time per character for development is available compared to other CGDCT anime, due to this show having a plot, but you're not left wondering what a certain character would do in any given scene.
Enjoyment:
I got a lot of great enjoyment out of the series, it was bright, cute, happy, and fun. The entire ride was comfy, but with enough bumps that it wasn't boring. I feel like they nailed the sweet spot for a balance in:
fanservice / moe
CGDCT/harem
plot/slice-of-life
drama/comedy
as well as tone and having great versions of a whopping 6 different types of loli waifus. The "main" girl is also pretty great.
Overall:
Overall, I'd say this show delivered a lot more than I expected it would. I'd say it's a CGDCT show with just enough plot and romantic spice to keep you from sinking into complacency. Also, it's about a band, they play music pretty often. You get to see an animated 3 piece loli band play music pretty often.
If that's not worth a 9, I don't know what is.
EDIT: The source material is a light novel released in 2012, along with a manga adaptation that started in 2014. Neither is translated by an official source, or a fan scanlator. If you don't want to be blueballed by an inability to finish the story, learn Japanese or don't watch the show. If you just want 5 hours of cute moe lolis in a band, regardless of story, go on ahead.
