[stonejag]

I owe two Datahands and used them daily for 15+ years before switching to Svalboard. I could type over 60WPM within the first hour - it's a very, very easy transition if you're already used to it! It took me a couple of months to get fully comfortable with Datahand, but a lot of this was learning how to quiet down unintentional finger movements, since you're using small muscles in unfamiliar ways.

Svalboard is way more adjustable (and therefore comfortable!) than Datahand - especially if you have small hands. It's also a massive, massive advantage to be able to change the keymap so easily - since it's running QMK underneath, you can use an online JavaScript-based tool to change any key to anything else! (and there are 15 shiftable layers, so you can also set up layers for individual apps or games etc). Macro support is great but the true killer app is integrating pointing devices into each side. Datahand had a very clunky up/down/left/right mouse emulation system, but it was incredibly awkward to use and therefore most users had a mouse as well. With integrated pointing (trackballs, Trackpoint or touchpad - mix and match) you never need to lift your hands out of the keyboard, so you can concentrate on finding a comfortable position without having to compromise so your mouse fits. The trackballs G Worm great, and using one for scrolling feels very smooth. Plus, there's an active user community constantly hacking in new features :)

The price gets mentioned a lot, and yes it is expensive. It's still cheaper than taking time off work, and for the amount of thought and design time it embodies, is probably undervalued. It's easy to fall into the trap of only considering the material costs of production now that the design is fairly stable, but bearing in mind this is one person's full-time job. There's also a very generous return policy, and a "let's try to make this work" option for students etc - so it's actually not as bad as it might seem at first glance.

Disclaimer: I'm a happy paying customer with very serious hand RSI and a long history of somewhat-successful surgical repairs. Svalboard allows me to continue working for hours at a stretch, where a flat keyboard would have me unproductive and in pain within half an hour. It might not suit everyone, but it makes a huge difference for those of us that need it!