I used 9x4 Thai keyboard layout on my 3.7" Nexus One. I mastered it and reached 40wpm without autocorrect/suggestions. After upgrading to 4.7" Nexus 4 I found that the screen is too big and I'd have to use swipe keyboard. I don't think I ever reached 40wpm again.
Then again, that was when in high school. Maybe my fingers grew bigger.