The newest Twiddler3 Firmware - version 17u - is now available for install.
Upgrade instructions and the download link can be found here:
This version of the firmware adds support for the Haptic Module, if it was installed at time of production, and a few minor bug fixes.
If your Twiddler is working fine, there is no need to upgrade.
If you like to have the latest firmware installed and you are running < v17, then install it.
If you are running v17b, this update is not critical but is recommended.