Disclaimer: It's not about typing fast, it's about comfort.
I use a Kinesis Advantage (more about it below) with a Dvorak-based layout and some personal modifications.
(Each key displays (from bottom left, clockwise): without modifiers, with Shift, with AltGr+Shift, with AltGr.)
Things worth mentioning:
- I have á löŧ óf węirđ-äśš łeŧtęrs ańđ I ačtuąlly üsé
allmost of them. I type in swedish (åäö), english, polish (ąćęłńóśźż) and northern sami (áčđŋšŧž - these in particular have a bit haphazard arrangement since I added them most recently and just had to fit them in somewhere). I also have norwegian æ/ø and german ü/ß just for convenience, though I don't use them much. - All characters that I normally need can be typed with Shift. AltGr is used for digits, special letters and a few uncommon special characters. Digits are arranged like a reversed numpad.
- The digit row is completely repurposed and mostly dedicated to C programming, with common sequences like -> and (); being very easy to type. The < > speed up markup work. I have the other special characters lining the edge of the keyboard.
- No dead keys (~, ^, etc); I have all the accents I need available through a single stroke. Strictly speaking, I don't really need capitals of everything (Ą, É, Ę, Ń, ẞ, etc), but they are included for completeness.
- While most swedish Dvorak (or "Svorak") users have ÅÄÖ in the QWE positions on normal keyboards, I've let the period remain in its default Dvorak position and instead made room for Ö on the left pinky.
- I have moved the positions of Delete and Tab, since I use the latter more often. I have also removed Caps Lock (it currently functions as an extra Tab, but I never use it - I will probably repurpose this key sometime).
- Down/Up have been swapped from the Kinesis default (Up/Down).
- Some of the function keys are shortcuts for window management and starting frequently used programs. F5 opens an xterm (or Explorer window, the few times I use Windows). F12 closes a window; at home this is done through my FVWM2 config, at work (where I mostly use Windows) F12 is macro-mapped to send Alt+F4.
- I have previously used a layout which also included cyrillic letters, but since my russian studies are on hold indefinitely I currently have no need for those. For a long time I had digits mapped so odd/even alternated on the left and right - I read somewhere this was the "proper" Dvorak way and wanted to try it. It worked but held no massive benefit and made the layout unnecessarily complex (... is this really a concern here?).
- The keys in the upper right are Kinesis-specific (they are used for reprogramming and accessing the built-in numpad, which I do not use). The "Scroll lock" key is especially scary since it sometimes powers my system down for some reason (I'm afraid to try it even as I write this). Fortunately, I don't hit it that often by mistake.
This way, I have achieved a keyboard that is almost impossible for anyone else to use (the most frequent visitor to this page is my girlfriend - hi there! - when she needs to use my keyboard and look up where a character is).
You can also check out this keyboard "mod" I made for an IBM Model M.
Praise for the Advantage
I've been using Kinesis Advantage keyboards for a decade now. The 349 USD (as of 2017) are slightly more than you normally spend on a keyboard, but they are definitely worth it (when I bought mine they were 299 - this was the original Advantage model, the Advantage2 is a bit more pricey).
Compared to standard keyboards I get a more relaxed typing position. The whole keyboard is curved so I can keep my fingers slightly curled back and reduce pressure on the joints. I also appreciate that the keys are aligned in straight columns so I avoid much of the strain from moving my fingers horizontally. Standard keyboards have slanted keys, a leftover from mechanical typewriters (the home row is offset by a centimeter or so from the bottom row, and the top row offset by another half centimeter from the home row). I have never figured out how to position my hands comfortably on those.
I also get efficient use of both thumbs. Normal keyboards have common keys like return, backspace and tab along the outer edges, so I must either use my (weak) pinkies or move my other fingers out of position. The Advantage isn't ideal either since it has the shift keys along the edges - maybe one day I will remap them to a more central position, but I can't decide which letters I would sacrifice for this.
The Advantage has hardware level key remapping and macros. I have made use of this at work, when I frequently had to move between different computers. I have swapped the keys around in the keyboard itself so I do not need to install any keymap - "plug and play" at its best.
(Getting special characters where I want them on Windows still requires software tweaking. "Microsoft Keyboard Layout Creator" [link was broken and I can't be bothered to find a new one, look it up if you need it] goes a long way but does not - unlike X - let me change the behaviour of function and modifier keys.)
Kinesis also have excellent technical support; I've emailed them a couple of times and they usually respond within the hour.
Of course, there are also some problems with the Advantage. I wish the whole thing was flatter (it's 3 cm tall at the front and 6 cm at the back). The USB connector on the bottom doesn't provide enough juice for any mouse I have tried, nor does it have enough room to plug a memory stick in at that angle, so I'm not sure what it really is for. When holding keys down for a very long time (when playing games; this doesn't affect normal typing) it sometimes glitches out and stops repeating (this doesn't happen with brand new keyboards, they just seem to develop this condition after a while). Finally I wish it had a few extra keys (even if they were "dummy" keys by default) to use for macros and customizations.
The function keys are wobbly and provide almost no tactile response (IMO they should be just like any other key, not this rubber thing they are now). They fixed this on the Advantage2!