Most annoying!

Its funny how typing becomes a learned response, you immediately notice when things are not in the correct place and you have to re-learn this skill. The keys are so much smaller it definitely decreases accuracy. It would be nice having a number pad like my large iMac keyboard but there is simply not enough real estate on an iPad screen.
Custom phrase is handy but that is also available in the normal keyboard.

Hutchoo about 123QWERTY: Customize Alphanumeric Keyboard Keys, v1.3.0