ErgoDox EZ vs Topre Realforce 104UB

You can map any key to any position easily using a simple GUI, including making hardware key layers. And, since the firmware is open source, you can modify it to do anything you want. Many of the hardware components can also be altered/replaced by equivalent parts.

You can arrange each side of the keyboard to match your hand positions. Helps keep your body straight and improve your posture.

Because of its split design, the ErgoDox lets you optimize the positioning of its halves according to what's best for your body shape, even if you have broad shoulders and large hands.

The ErgoDox has an open design, so if you want to modify anything at all, you can fork the Github repository.

There are more keys which are easily accessible for touch typists than on common keyboards.

Unlike other keyboards, like the Lexmark M15 and Cherry G80-5000, where the only action performable by the thumbs is punching the spacebar, ErgoDox has extra keys placed near the spacebar, within thumb reach. This prevents the thumbs from being a bit redundant.

Almost all the keyboards have a small row offset (for example, on a standard QWERTY keyboard, the A key is not directly below the Q key. On the ErgoDox, this isn't the case: keys form straight columns. Together with the movability of the two parts you can stretch your fingers straight on, not slightly sidewards. This helps with touch typing, since you just need to stretch your fingers straight onward to reach the key above, rather than stretching it onwards and sideways.

Because of the nature of ErgoDox, within an open source community, there are advancements in firmware being made continuously.

With most programmable keyboards, you have to use their software in order to save and reuse your customizations. Using such keyboards on other systems "degrades" them to their default setting. Since with the ErgoDox the settings are saved directly on the keyboard, no matter the system where you're using it, your macros, tap dances and layers are always available.

The Ergodox doesn't allow you to reach over the centerline to hit T and H with a single finger, or whatever other bad habits you might have. The split design forces you to keep your hands in the right position.

The pre-assembled version offers an extensive 2-year warranty, provided you haven't taken it apart or physically broken it.

You can put the keyboards together, making it very easy to carry around.

Topre switches are a mix between mechanical switches and rubber dome switches. They have mechanical components, however they are covered beneath a rubber dome which protects the switch. They bring a mechanical feel, and mix it with the durability of a rubber dome switch.

Variable weights under each specific groups of keys was done in a bid to prevent RSI (repetitive strain injury). For instance, the groups of keys that the pinky finger hits are much lighter/softer than the rest of the groups of keys that are pressed by the rest of the fingers. Variable weights are achieved by having either heavier or lighter rubber domes. Whilst this idea is very useful for normal typing, for gaming it's not so great: for instance, when dealing with First Person Shooter games that requires WASD keys, those sets of keys feel very light when fingers other than the pinky are used to actuate them.

Silenced Topre switches are designed for those who do not particularly like the sound of keyboards being tapped on or for those who may be concern over disturbing others when using a noisy keyboard. Silencing is done mainly by placing a material that absorbs the sound of the slider when it makes contact with the slider housing. This thereby prevents excessive noise when the key has been released after it has been actuated. The overall effect of a silenced Topre is quite astounding as it may give the impression one is on a cheap keyboard (obviously, the reality is actually the opposite).

PBT (polybutylene terephthalate) keycaps last longer than other keycap materials, and are more durable. They are more expensive than ABS (acrylonitrile butadiene styrene), which is why they are less commonly found.