Total Recommendations: 2
Both of the movie is basically a kids movie with the idea of "let's throw cool shit on screen and hope it makes sense." Which in the long run is not a bad thing per se. It shows the creative ideas and concepts that the everyone working on it had and it works. Fun movies, not taken seriously, just enjoy the gorgeous eye candy.
It is basically the same thing just without a soul eater flare to it. There is no over arcing plot. Just a group of cute moe girls doing whatever each episode. If Soul Eater Not was made the same time K-ON was made, it would have been very popular but it's not. And to be honest it feels out of place with the rest of line in the spring season. But as I digress, if you really like Soul Eater Not then K-On is right for you and vice versa