I'm about halfway through The Last Guardian now and I'm really enjoying it... though it's not without it's quirks. The jumping is sometimes incredibly clunky, and I've had a couple times where Trico has just not wanted to do the obvious.
Had one moment which was supposed to be really cinematic as I fell through the air to certain death before Trico launches his tail out for you to grab onto. But when I first did Trico didn't swing the tail over to me and I had to try it again. Did the same sequence but changed the angle of my jump by an extremely tiny amount, and this time Trico did move his tail over to me. Very frustrating and a great moment slightly spoilt.
But for the most part everything works really well and the AI is just incredible. Most believable animal I've seen in a game. So far it hasn't been as poignant or as melancholic as Ico or Shadow Of The Colossus, but I'm hoping that changes.