My brand new Zotac GTX 780 Ti just arrived and it's awesome!
When it comes to Blender, it's 4 times faster than my old card. (560 Ti)
Here's a glass cube, rendered in Blender (Cycles) with 30000
samples. Took merely 17 minutes. Absolutely noise-free.
Also played some Crysis 3 today. On max settings, with 8x MSAA. Got way more than 60 frames per second.
TL;DR: New Graphics Cards is awesome, expect way more Cycles renders in the future.