This is just a honest review from a regular anime watcher so if your looking a detailed one its not the right place. To begin with if you're looking for action, like in the main story, it's not the right place to search. I agree That these special series are worth watching and are funny, but its definitely lacks the entertainment which the main story was packed with. Would I recommend to watch it ? Definitely. Will you have fun while watching it ? It depends on your expectations, but I'll say that it's worth spending your time. So all in all 7/10.