The Kinesis Advantage2 is a uniquely-shaped ergonomic keyboard that is the best at preventing injuries associated with prolonged, incorrect hand posture and finger strain. The key layout is designed so that it can be used in the most optimal way possible, with a set of keys assigned to each finger. All these factors combine to make the Advantage2 the best option for enjoyable, rested and productive programming.
Pro Tweaked layout that saves your hands
This keyboard has numerous ergonomic advantages over a keyboard with a standard layout. Some of them are obvious and some are subtle, but they are synergistic and result in a typing experience that places far less stress on the hands. Learning a tweaked keyboard layout is a small price to pay to avoid RSI (repetitive strain injury).
Pro Clusters of keys under each thumb means less reaching
Having multiple keys under the thumbs lets you keep the rest of your hands still, and helps prevent reaching. For example, the backspace key on a regular keyboard is way in the top right corner, while on the Kinesis keyboard it's under the left thumb. So, to hit the backspace button you just need to move your thumb while on regular keyboards you need to move your whole right hand and stretch your pinky to reach it.
Con Can be a bit flakey at times
The downside of this keyboard is that it can occasionally act up. The biggest problem is that the up-event for a key occasionally gets lost and then some key will auto-repeat until you press it again. Or even worse, it's a key that has no visible effect like an Alt key, and then you have to figure out which key it is that is in the virtual down position, and press it again. It has had this same problem for the last 20 years. You learn to live with it for the sake of your hands.
Con Different switches for the function keys
The functions keys are not build with the same switches than the other keys: they use Cherry ML switches instead of Cherry MX Brown switches. Because of their shorter travel distance, the ML feels quite different. It's awkward to have such different sensations for different parts of the keyboard.
Con Proficiency means overcoming a learning curve
Becoming an expert at using this keyboard’s optimized design needs time and patience, since it’s so different from what most people are used to. Some of its drastic layout changes can be disorienting at first. For example, the four arrow keys are separated: up and down on the right side cluster; left and right on the left side cluster.
It’s also built to enforce healthier hand posture and movements, that may feel weird at first. For instance, the keyboard trains you (using a deactivatable key feedback) to press keys smoothly instead of smashing down, which reduces hand strain. Usually, it takes between two to four weeks of regular use to feel completely comfortable at using this keyboard.