I believe it worth it for the ease of typing. Qwerty feels like a lot of work while typing fast, Dvorak seems less jarring.
After I first learned Dvorak, it was hard to switch between it and Qwerty. It was almost like I had replace Qwerty with Dvorak. After I had spend about a year or so switching back and forth between the two, all I had to do to put my brain back into Qwerty mode was to glance down at the keyboard layout to remind myself.
Now that I've been using Dvorak for 8+ years, just being at someone else's computer instead of my own is enough for my brain to switch back to a Qwerty context. In fact, if I've switched someone else's computer over to Dvorak, my brain will often stay in Qwerty context and I will forget or feel weird typing in Dvorak for a few minutes.
It's analogous I think to bilingual speakers. It may take a few seconds to sort out which language you need to use to communicate to the person in front of you, but after that you lock in and can continue without a problem.