Maybe it's because I've been watching a lot of stuff lately, but of all the KyoAni stuff that I've seen, the only thing that looks completely different is Lucky Star. Everything else seems to share the same base design.
As for licensing, I still don't know how you sell the DVDs. It just doesn't work with the first season box set (which I think is awesome, but I'm a nerd) and most people probably didn't enjoy the whole Endless Eight thing enough to want to buy something that features 8 episodes with the exact same plot.
They might have to do a "chronological order" box set just to balance out the wackiness of S2.
I do agree that Sighs is fairly unexciting... probably because the movie opens the series. I haven't been compelled to finish off what remains. (I still need to start Tokyo M8, although the Internet seems to have turned on it and shunned it to hell).