The firmware update will make both models quicker and more responsive, it also gives them a boosted EV compensation range, a new menu option to allow shutter release and an increase in exposure bracketing, you can find out fully detailed information regarding the updates here.
The new firmware versions and full installation instructions can be found here, the process looks pretty straight forward basically you download and extract the update, format your memory card, copy the update file to the memory card and finally update your camera’s firmware update by putting the memory card in the camera and then turning the camera on whilst holding the menu button, it should then ask if you want carry out the update, click OK.
Here are some screens showing the process:
You can find out how to utilize the new functions here. Have you installed the update? If so, are you happy with the new changes?