I learnt Dvorak in 2 weeks and got back to my hunt-and-peck QWERTY speed within a month, within 2 I was typing 60-70WPM without effort, and about 90% accuracy. I did this with no formal training and my only motivation was that at that time I couldn't afford an "ergonomic keyboard" and had heard that Dvorak was better, so I gave it a try. It's also an ANSI standard so I didn't have to install any weird software, just choose it in the operating system settings.
I no longer have shooting pains up my arms. Whether that's a result of the ergonomics of Dvorak, or simply that I can touch type, is not something I'm qualified to answer, but what I can say is that:
- Dvorak is easy to learn
- only takes mild motivation to get good at
- is more comfortable
which leads to better typing habits that are good for you physically and make you a faster typist than hunt-and-peck, with less effort than learning to touch type on QWERTY.
Would I learn Dvorak these days over another layout like Colemak or whatever is the favorite today? Yes, I would, because it's a standard. I think we're at diminishing returns (for English) so it doesn't really matter: anything is better than QWERTY, even ABCDE...