IIT is provides a mathematical approach to measuring consciousness. It is not crazy, and has a significant number of good papers on the topic. It is human-independent
I don't understand it, but from reading the wikipedia summary it seems to me it measures a complexity of the system. A complexity is not necessarily consciousness.
According to this theory, what is the key difference between a human brain, and... let's say a hard disk of the same capacity, connected to a high-resolution camera? Let's assume that the data from the camera are being written in real time to pseudo-random parts of the hard disk. The pseudo-random parts are chosen by calculating a checksum of the whole hard disk. This system obviously is not conscious, but seems complex enough.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.