I cannot say much about those prototypes since I only heard about them long time ago and never touched a real one. In fact few people even know about those silly stuff anyway…

Inputting Chinese on a keyboard is hard because of the sheer amount of characters. There is no feasible way to have enough physical keys mapping to even a very limited subset (think 2+k chars as the bottom line).

So the way out is to use Input Method Editor (IME's) to map a sequence of keystrokes on an ordinary US keyboard to a single Chinese character or phrase. Currently in mainland China there are two families of IME's that are in wide use: Pinyin-based and Wubi-based.

Pinyin-based IME's converts Pinyin, basically the sound of Chinese characters in Roman alphabet, to the corresponding chars. This family of IME's is the most popular one because almost any kid born after 70's knows Pinyin, and thus the learning curve to use Pinyin-based IME's is just mastering the keyboard itself. The shortcoming of Pinyin-based IME's is that a single sequence of Pinyin can translate into a lot more chars (1:50 ratio is quite common), and the user has to choose which one is intended. This is considered rather slow and error-prone. Most modern Pinyin-based IME's focus on NLP model to predict the correct chars, and I have to say it is now much much better than 10 years ago.

Wubi-based IME's rely on a formal and rather complicated method to decompose Chinese chars into sub-components based on shape, then map the 26 alphabet keys on a standard US keyboard to these components. The user chooses the correct components to form the characters. The advantage is that a single char requires less than 4 keystrokes to input, which is considerably faster than Pinyin-based IME's which usually require more keystrokes. There is also much much less “hash collisions” in that a keystroke sequence usually maps to only one or two chars, thus no need to manually choose anymore. The downside though, is that the method to decompose chars into components must be memorized, which is very difficult, and the mapping of components on the keyboard must also be familiarized, which is even more confusion. Some keyboards come with extra labeling to help this, much like a typical Japanese keyboard. In addition, I have the feeling that this method is designed for professional typists instead of ordinary users because it is quite counter-intuitive to think how chars are written and then decompose them when you are just chatting with someone. Professional typists, on the other hand, are looking at existing documents and try to input them into a computer, which is quite different from the mental model of chatting.

There are other less used IME's too. For example bank representatives used to use a method that map a 4~5 digit number into a char purely on the numpad because it is considerably faster once you master it. I don't think anyone is using this method anymore though. The learning curve is just insane. Other IME's try to combine both Pinyin and Wubi together with different tradeoffs, but few gain real traction.

In Taiwan and Hongkong there exist different IME's because they use Traditional Chinese which have much more complex strokes than Simplified Chinese used in mainland. Also in Hongkong they speak Cantonese whose pronunciation is different than Mandarin, so normal Pinyin is not used there.