I've been watching this series lately.
The art and animation are pretty good by most standards. There are some scenes in the series - like the famous rock concert scene - that are so smoothly animated it's almost unreal. You can really tell where they spent the animation budget.
The plot is a little confusing. The characters clain to be aliens / time travelers / espers but don't go out of their way to demonstrate it. There are moments, however, where it becomes apparent that they are telling the truth about themselves.
The main character is just plain confused about the whole situation while all of his friends in the club seem to have an adequately clear understand of what's going on - leaving him rather clueless.
It's a fun series. I hope the story continues to be interesting.