If any of your components are on air, I recommend the HAF-X hands down(also substantially cheaper)
If you are going to water cool the CPU AND GPU, then the 800D is good too.
Basically, the HAF-X is the cadillac of air cooling cases, that also has very good mount options for water cooling, as well as other amenities.
The 800D inhibits airflow in comparison the HAF-X and costs a bit more(I think $100 more)
I've worked with the HAF-X a few times, and it will be my next case.