I watched the season premier a few nights ago and I actually enjoyed it. They tied up a lot of loose ends.
For instance, the aliens did not invade in 2012 after all because they decided the planet was getting too warm and the natural resources were dwindling. Saved by global warming? Granted that was an awful lot of planning only to change their minds. Phase one of their plan began way back in prehistoric times when they began depositing the black oil genetic material in the earth.
Also, they brought back some of the older characters like agents Spender and Reyes. Seems to me Spender died a long time ago but apparently they found a way around that. I still can't remember what eventually happened to Mulder's sister, Samantha. His quest to find her was the original basis of the series. No doubt they'll find a way to bring back the Lone Gunmen, maybe even Agent Krycek too while they're at it.
What I disliked more than anything was the Smoking Man's frequent assertions that he was Mulder's biological father. It was too much like Darth Vader and Luke and it almost seemed like they were playing it for laughs.