You make very good points about alternating between hands. The strength of the Dvorak keyboard is that a high percentage of English words are typed in an alternating pattern. In QWERTY there are a lot of words that require typing two consecutive letters with the same finger. In Dvorak, there are quite a few words which can be "rolled". In fact, my most common typing mistakes in Dvorak are hitting the keys in the wrong order because I can basically "press" the word, and it's a matter of the keystrokes landing in the right order. QWERTY typing has a much rougher rhythm to it.
