The first half of this season doesn't continue with the story, rather it focuses on fun activities during summer vacation. I always enjoy these settings as they are relaxing and full of comedy. Basically, these episodes are more funny than anything from season 2 and time well spent with all the characters we know. A great way to see everyone outside of the serious environment and just be care-free.
The last half of the season goes back to being serious and focuses on the story of where we left off in season 2. It is decently interesting then what should be the big moment of action in the last episode becomes really uneventuful as all the epic build up ends in a single shot. We are given a couple of touching lines and somehow everything is over just like that.
The flaw to the story issue is this silly 10 episode focus rather than the standard 12, which hurt the ending of S2 clearly and now feels like it somehow skipped past what should have been an epic fight just to squeeze it into 10 eps. There just isn't any logic or reasoning that can justify this issue.
Aside from that, the summer activities followed by going back to the story till just before the last episode are really enjoyable. All missing points are due to episode 10.
The ecchi/suggestive content increases compared to season 2, primarily noticed during the summer activities early on.
The short preview into Season 4 looks promising with some new additional characters and hopefully more focus on retrieving the 8th card.