TotalBiscuit's review for XCom 2 is out. His reviews are usually pretty comprehensive. No major story spoilers are in the review.
https://www.youtube.com/watch?v=W1dLGihV0NoHe at one point outright said that if you liked the 2012 remake, then you will like XCom 2. Overall, he really liked it, but he liked the 2012 reboot as well.
Some other takeaways.
Needs optimization and is still pretty buggy. Nothing new there.
The geoscape seems much improved in that there is more freedom and less forced missions, but base building has been further dumb down. I didn't even think that was possible given how simplistic the 2012 base building was.
Tactical Combat is basically like the 2012, but more polished and faster paced. Also there are still soldier classes.
Still only three tiers of weapons, but lots of upgrades and misc equipment to add more variety.
Did not see a single HWP. Guess those are gone completely except for the support class's drone.
There is going to be a lot of mod support out of the box. I think there are already people modding it and the game isn't even out yet.
In summary, if you hated XCom 2012, then skip XCom 2 since it is basically XCom 2012 with more polish.