Potential plot spoilers ahead. You have been warned.
I watched this series live in Japan while I was working/training there.
Visually, well, it's KyoAni. Moe, funny, titillation, etc. I personally like the art style, but your mileage may vary, of course.
As in series 1, the cast fit the characters like a glove, the writing is top-notch, and the direction is on point. The soundtrack and the new OP/ED themes are outstanding.
So why did I stop watching after 10 episodes?
Well, I would imagine this might have something to do with the decision to do the (actually very short in the novels) Endless Eight arc in 8 22-minute episodes. That's well over half a cour for at most a single light novel volume. I know a lot of decisions are like "Well, we didn't know it might flop at the time", but come on, a little imagination would've revealed this to be an absurdly bad idea.
Er, wait, imaginative Japanese management/producers? Forget I said that.
I got the joke at the second episode. "OMG they're going to do 8 of these, aren't they? Lawl."
By the fourth episode, the joke was no longer funny.
By the seventh episode a ton of viewers and I were like "GAAAAAH MAKE IT STAHP."
The problem with this decision, as you might imagine, is that other than explanatory scenes in latter episodes of the Endless Eight arc, each run through the causality loop (that's a Trek reference) is basically identical. I bet they've thrown in little variations here and there, but playing Where's Waldo? with anime like that is not my idea of a fun time. Now, this is fine if you do it in 5 to 7-minute chunks of a single 40-minute (ish) episode like in Star Trek: The Next Generation. If you expand those chunks into 22-minute episodes... well, let's just say I was skipping to the end after the 3rd run-through. "Did they stop the loop? No? OK, see you next week."
By the time the next arc (The Sigh of Haruhi Suzumiya, AKA the lead-up to the hilarious troll episode in series 1) rolled around, I was exhausted with Haruhi, and my scheduled time in Japan was over. The only reason why the story isn't rated any lower is because they delivered a masterful punch line at the end of the loops... but that wasn't enough for me to continue slogging through another major arc.
I might pick it up again, but this is an example of how one decision can ruin the entire experience.