Zotac offers a completely new performance level at this size with the GeForce GTX 1080 Ti Mini. If your case does not have room for monstercards of 27 cm or even longer, a GeForce GTX 1070 was the fastest card you could install up until this point. While it is not the fastest custom 1080 Ti because of the obvious limitations, the GTX 1080 Ti Mini does perform 50% better at 4K-resolution than the aforementioned 1070s. This can be the difference between fine and unplayable in a lot of games and is a big achievement.
If you do have the room for a bigger card, we would always utilize this room. Especially considering the noise levels there are compromises you really would not like to see. Under load only the Nvidia Founders Edition produces more noise and in idle the presence of the Zotac is always noticeable. Nearly every other custom 1080 Ti is passive in that case, but this one is not.
Nevertheless we can definitely see the use case of the Zotac GTX 1080 Ti Mini: a compact game system under a new 4K-television, in order to play recent games smoothly at the native resolution. With the power of a GTX 1080 Ti this is a lot easier than with a GTX 1070. The Innovation Award is well deserved, but if you purchase it you will have to live with the negative sides of this little king.