This is the first time I've written a review on MAL, but I feel the need to because I think all people see when they look at this anime is Super Sonico and all that she and her merchandise implies and automatically discard it. While I can't really blame them for that because the merchandise implies a lot, I gave it a chance and was pleasantly surprised. While it's no masterpiece, the fanservice was mild, the characters outside of Sonico were actually interesting and engaging, the soundtrack was excellent, and overall it was enjoyable to watch.
The anime was fairly episodic, and it didn't
leave much for the fairly simplistic overarching plot of Sonico coming into her own as a band member and a model, but it was still well executed and the episodic subplots were well done and all contributed something to the base plot.
It got across the point that it needed to and it didn't detract at all from the anime with too much 3DCG, low quality BGs, etc.
The music in the show was excellent and always fit the mood very well. The OP and the multitude of EDs were all well done and Sonico's band, First Astronomical Velocity, had quite a few catchy and well orchestrated songs. With the premise of the show being musical in nature, the good soundtrack gives it a good boost and made it fun to watch.
This is I think where this anime shines, and interestingly enough not because of the main characters, but the supporting characters. Every episode Sonico would go through some kind of ordeal that involved a side character that would develop throughout the episode and end up being affected positively somehow by her. They all had interesting backdrops to their scenarios and were given ample characterization in the small amount of time they were featured, and each one in some way or another contributed to the overall plot of the anime. There were also a few side characters that were in the background throughout the series that saw gradual development such as a chubby girl that came to terms with how she looked and even learned to embrace it through Sonico.
The anime was made fun with the high quality soundtrack and the color saturated visuals, and each episode had an interesting premise with engaging side characters. It's not a must watch, but if you're looking for something to just casually watch that you'll enjoy for its simplicity and episodic nature, you won't be disappointed.