I use Dvorak. I never bothered to maintain the QWERTY keyboard for vim movement. Now, it seems completely natural to navigate with the Dvorak mappings for h,j,k,l, etc. I can't easily navigate one-handed, I guess, but that is never really a problem.
Switched to vim and dvorak same day five years ago. Default mapping is very natural - left hand (qwerty "c" and "v") used for vertical movement, right hand (qwerty "j" and "p") for horizontal movement.
That article is probably doing more harm than good. Using Vim with Dvorak came as naturally as switching to Dvorak from QWERTY (that is, it took some work, but now I wouldn't use anything else).