At least for me, the film is a disappointment, especially since it's the conclusion of the OT.
-> Useless and boring first act: Tatoine once again, Jabba sucks, and the pacing is terrible.
-> Bobba Fett's terrible death.
-> Han is back to do nothing?
-> Deathstar again, and in so little time? TFA shares a similar problem, but Starkiller isn't really another deathstar.
-> Almost no character development for Luke. He's already a Jedi Knight from the beginning and they had to retcon Leia as his sister to have any challenge for him in this film. All he does is "gotta convince my father -> Resist falling to the Dark Side after having his sister threatened -> Emperor tries to kill him -> Saved by his father".
-> Darth Vader desconstruction. He's a merciless antagonist in 4 and 5, and then when he's revealed to be Luke's father he's not anymore?
-> Leia being Luke's sister sucks and makes the whole saga a family drama.
-> Ewoks are boring, and the final battle in the planet between the eworks and the empire is terrible. At least it wasn't the Wookies planet, or it would've shrunk the universe even more.
-> Space battle isn't great too, it's basically "we're fucked until the heros disable the shield and profit". Compare with the tension from episodes 4 and 5 (or 8) space battles and how much more happens in these battles.