I came from the Droid, to Droid 3, to now the Galaxy Nexus.
In terms of OS, the Galaxy Nexus destroys the Droid 3 in.. every way possible pretty much. Especially now that Android 4.1 is out.
The keyboard.. well, the Droid 3 is perfect for texting while driving.. it was definitely safer if you had to send a quick text at a stop light or something as you didn't have look at the keyboard to type most of the type. The Nexus.. don't text while driving. It's basically impossible. However, texting normally, I find that the keyboard on the Nexus is faster and easier to use.