There are plenty of alternate keyboards available on the Playstore and you can install them without rooting, if you’re disappointed with the stock keyboard. I use Swiftkey 3 (and sometimes Swype) myself, which has a powerful prediction engine.
Google has updated the stock keyboard on Jellybean (Android 4.1) which is pretty much like Swiftkey.
Install Jellybean on Android 4.0.3 or higher
If you’re one of those 10 percent of people who have Ice cream sandwich (4.0.3 or higher) on their devices, you can get the Jellybean keyboard right now. Head on to this XDA thread, and download the beta 1.2 version of the app (of course, you need to send the .apk file to your phone and install there).
The keyboard’s prediction engine is pretty solid, but I still prefer that of Swiftkey. Though, I like the interface of this keyboard, because it looks much simpler and holo theme is always nice to have. It’s also pretty smooth without any lag, if you’re experiencing any lag, then be sure to turn off ‘Popup on keypress’ in the settings – it will be significantly faster after that (that applies to many Android keyboards).
You can also customize the vibration duration, themes, keyboard layout and all under settings.
According to the developer, the app won’t be put on Playstore and will be under constant development, so keep checking the thread for newer versions of the app.
Link: Jellybean keyboard