I once tried a typing speed test on my iPhone and compared it to my physical keyboard I always type with on the PC. I think on the on screen keyboard (OSK) I was reaching over 60% of the speed of the full sized keyboard on the PC.
This was really surprising for me, as also the precision was not really worse than on the PC.
I have to admit that I can't type perfectly with 10 fingers, but reach around 350-500 keystrokes per minute, which is far beyond average.
So the OSK is fine for me, as long as the UI is handling the missing screen space well, and doesn't provide a bad UX, like jumping scroll positions or covering important buttons by the OSK.
This was really surprising for me, as also the precision was not really worse than on the PC.
I have to admit that I can't type perfectly with 10 fingers, but reach around 350-500 keystrokes per minute, which is far beyond average.
So the OSK is fine for me, as long as the UI is handling the missing screen space well, and doesn't provide a bad UX, like jumping scroll positions or covering important buttons by the OSK.