This game is incredible; having a blast with it. I never played with the Long War mod, so I'm not sure which things were inspired by it, but there are a lot of improvements over the original XCOM. Overall, the design of the game is solid and smart. Effects-wise, I'm even leaving the action cams on (used to always disable them in the original XCOM) since they're done so nicely.
The graphics are a bit demanding as you start to raise the overall quality preset. It seems a lot of folks are having issues, even with modern GPU's. Though, thankfully, the game can still look great at the lower settings.
For me, the game isn't about sexy, realistic graphics; I favor gameplay and ultra-smooth frame rates and performance.
I think with some tweaking of the graphics settings, beyond just selecting the preset option at the top of the list, one can get an even better looking game without sacrificing smooth gameplay. For instance, anti-aliasing is a very demanding setting and will drop your frames fast.
Here are my settings so far with my two old GTX 560 Ti's in SLI:
(Also, a few days ago, I finally "took the plunge" into Windows 10 and did a clean install with it... things are running nicely overall.)