There's not much left to say that hasn't already been said about the first series. If you liked that one, you will like this one, but as usual the sequel isn't going to win you over for the franchise.
There is one thing that's different: the focus seems to shift away from the three sisters for a bit, and instead more of the comedy comes from the supporting cast. That's refreshing: there's only so many fights between Chiaki and Kanna you can show without the gag wearing thin.
There is also a series of heartwarming episodes where the three sisters try to lure the boy who lives next door out from his shell. But that is as far as it goes with respect to an actual plot -- after that's been resolved, it's back to gags again.
All in all, a 7, just like the earlier incarnation, because it's hardly a separate series.