I hate it when I have to click a 123 button to get symbols to pop up, and then I have to click ABC to go back. Although i have no idea how this "problem" would be solved, it is a slight hinderance for me.
This is not a problem if you simply do this:
If you're on the alphabetic keyboard and need a symbol on the secondary keyboard, simply touch the [123]. This immediately brings up the second keyboard. The trick now is that after you touch the [123] button, DO NOT LIFT YOUR FINGER; simply slide it to the symbol/number that you need and then lift your finger. This will insert the symbol at the space you left off at AND will automatically revert to the alphabetic keyboard