Now, I'm a fan of Haruhi Suzumiya and the crew, and when I found out that there was going to be more episodes added, I was definitely happy. But I'm currently watching the episodes titled "Endless Eight". Now, these episodes revolve around the idea that the characters are caught in a time loop, and the repeated episodes reinforce this idea. Well played, KyoAni.
But honestly, EIGHT EPISODES? That means six episodes are just meaningless fillers. That means TWO HOURS of pointless repeats of the first episode. I'm not saying you shouldn't watch the "second season" of the show, but be warned - the Endless Eight takes some strong will to get through.