Which keyboard is better: physical or virtual?

The first Blackberry mobiles featuring OS version 10 will not have a physical keyboard. Which keyboard is better: physical or virtual? A study by James Clawson and others from the Georgia Institute of Technology found that the mini-QWERTY keyboard (found on most Blackberry-like mobiles) allows expert users to sustain a typing rate of almost 60 wpm over the course of a 20-minute typing session. However, researchers are also working on making virtual keyboards better. A study by Niels Henze, Susanne Boll (University of Oldenburg) and Enrico Rukzio (University of Duisburg-Essen) found that visualising the touched positions using a simple dot decreases the error rate by 18.3 per cent but also decreases the speed by 5.2 per cent.