Far better than the reviews let on

Rating: 9/10 (5 December 2014)

First, I'm assuming that you've seen the other two Hunger Games movies...else there's not much point to sit through Mockingjay Part I (MJPT1). Second, I'm assuming that you're not a huge Transformers fan and/or didn't think that Pacific Rim nor Sharknado were the height of cinematic perfection.
After the first two movies, we already know a lot of back story and setup/conflict between Katniss and Pres Snow. Mockingjay PtI then introduces us to District 13 (her destination as mentioned at the end of Catching Fire) and the District 13 society (only lightly limned in MJPT1). We know there's a war coming and MJPT1 sticks to the story line as outlined in The HG book(s) to a great degree.
In terms of the movie and expectations, I never got the least bit bored nor did I feel I was just being dragged through Pt1 primarily to suck money out of me. There's a lot of there-there to be discussed, outlined, and philosophized about and, if you pay any attention, lots of action, too. Sure, this installment is a lot darker but that's how the story plays out.
If you compare the structure of THG to LOTR, you know what the protagonist has to do: The Capital is Mordor; Katniss is Frodo; she's the Mockingjay and he's the ring-barer. Neither has an enviable job -- just a sadly necessary, burdensome one. You know where Katniss eventually has to go and MJPT1 does an excellent job of setting this in motion.