I used dvorak for a few years, and have now been using halmak for a little over a year. The reasons to switch to alternative layout shouldn’t be speed, but mainly comfort: all of these alternate layouts result in miles less of finger travel. If you use a computer for your job, or just frequently, you might as well optimize how you interact with it.

The concerns below about shortcuts and vim aren’t really an issue: you just learn and get used to the new shortcuts, in the same way you get used to typing new words. I’ve done this with vim twice, it takes maybe a week to get used to where things are; not nearly as long as getting used to typing all of your most frequently used words.