The Corsair 780T is a FULL tower case, so, it's definitely going to have more space inside at the expense of having a bulky case. If it's only an AIO and a single GPU you'd put in there, it's up to your personal taste if you want such "void"/blank spaces inside which is also emphasized with the large side panel window:
Sample Build (Corsair 780T + NZXT Kraken x62 + GTX 1080 Ti):
https://pcpartpicker.com/b/TfyXsY
On the other hand, the NZXT Noctis 450 ROG is a MID tower case, which is relatively more compact than the case above. It still can fit such intended limited number of components easily, and with such, plus a smaller window area, looks more "complete"/less blank spaces inside to fill up:
Sample Build (NZXT Noctis 450 ROG + + NZXT Kraken x62 + GTX 1080 Ti):
https://pcpartpicker.com/b/TfyXsY
Between the two, and assuming you won't do multi-GPU setup and/or custom-loop water cooling, I'd prefer the Noctis.