I doubt anybody has subjected themselves to a rigorous study on the subject. What the people I know have done is this: try the handwriting recognition for a fe

I doubt anybody has subjected themselves to a rigorous study on the subject. What the people I know have done is this: try the handwriting recognition for a few days, go back to zhuyin or maybe wubi for a day or two and then go back to handwriting because they believe it's faster based on their own experience. Non-standard writing and simplifications are recognized in many cases. It's far from perfect; it's just a bit faster and more convenient than their old phones.