We had problems with typing accuracy and speed on Nexus One from the get-go. At first, we though it was because we were not used to the Android keyboard. However, after four days the results are pretty much the same, with only moderate improvement.
We used the same typing technique on the Nexus One as on the iPhone: either holding the phone in the palm of your hand and typing with one thumb, or holding it with two hands and typing with both thumbs.
One issue is definitely the accuracy of the touch. The tests from Moto Development Labs showed that the iPhone touch interface is more accurate. Some people can argue that the test is not accurate, but just from our own experience going from the iPhone to the Nexus One, we've noticed that the touch inputs are not as precise as on the iPhone, and we had to be more accurate with our aim.
A second issue is the screen width. If you look at the specs, the Nexus One' screen is 3.7", measured diagonally – 0.2" larger than the iPhone. But, the iPhone's screen is wider (2" versus 1 7/8"). This makes the iPhone keyboard 1/8" wider.
The image above shows how the two keyboard screens overlap. It's clear that the iPhone has the larger keyboard, which explains the greater typing speed and accuracy compared to the Nexus (in our case).
(For doubters and the curious, who wonder how we scaled the screen shots to reflect actual size, we took pictures of both screens with the camera the same distance from each phone, overlaid them in Photoshop [with the partially-transparent Nexus keyboard on top], then scaled the composite to the actual size of the iPhone screen.)
At first, we could not believe how big a difference 1/8" made in a keyboard size, but when you take a ruler and look at 1/8" on the Nexus, you will see that scale is correct.
While you type, Android provides suggestions (same as the iPhone); we haven't noticed any difference in the accuracy of the suggestions. Some reviewers reported that the iPhone had a better suggestion engine, but we cannot attest to that. Bottom line: suggestions on Android worked well for us.
In conclusion, typing on the Nexus took some adjustments. Its lower typing accuracy and speed is not detrimental to our needs, but definitely noticeable enough compared to our iPhone. Because the keyboard is a bit narrower, we had to focus a little bit more on aiming when typing. We feel a slight re-design of the Android keyboard layout can improve accuracy without changing the width of the physical screen.
Keep in mind we did not try to quantify or otherwise test typing speed on the iPhone vs the Nexus One. We simply wanted to share our experiences and gut feelings.
And while we may not be happy with the Android keyboard, our opinions on the integrated voice recognition as alternative input method are the complete opposite. We love it, and will talk about it in a subsequent report.