“Reset setting“ is an important feature that will be added in the next version of Ubuntu Tweak. After every resettable option, there will be an reset button. The tooltip will tell you what is the default value, and you can reset the value by just one click (See screenshot bellow).
Image credit : blog.ubuntu-tweak.com
The testing version of Ubuntu Tweak (0.5.6) has been entered the testing source, so if you want to test this version and help ubuntu tweak become better you can add the testing ppa bellow :
sudo add-apt-repository ppa:ubuntu-tweak-testing/ppa
sudo apt-get update && sudo apt-get install ubuntu-tweak