I love it. I think they are doing a lot to do two very important things: develop characters and keep the plot fresh.I love how much the day changes with Hopper's decisions. Seriously, people aren't even wearing the same clothes based on his choices. How fun!
I also love that the characters are growing more complex and three-dimensional. It's so easy, I think, to leave Chad as the annoying ex-husband, but Hopper's relationship with him is growing and changing in spite of it being the same day over and over.
I think they have done much to keep this show fresh and unpredictable. I love that he can die. I love the mystery. I love the confusion. It's a wonderfully engaging show, and I'm so glad, actually, that Lost is on hiatus. What a gem.