I have used Dvorak fulltime for about a decade and I'm much worse at qwerty than I used to be. I can get back up to speed, but it feels like reciting a poem I used to know and I can't actually think about what I'm doing.
I think it's about how often you switch keyboards. I switch between Windows and Mac keyboards daily (work/home) and now I rarely make a mistake when trying to use a shortcut. Same thing happened when I was learning russian keyboard layout, at first I wouldn't be able to switch despite knowing both layouts. Now I talk with two people simultanously, switching between russian and english (qwerty) every sentence
