No driver updater is fully safe to use since it’s always hard to known if their driver sources are reliable, your best bet is to either do some really digging into the programs sources for drivers or individually update each one (Go to your device manager and look through all the drivers and copy each one then go on google and search for their updates, if any).

CNET users seem to have mixed reviews on this, I recommend you look into it.

http://download.cnet.com/SlimDrivers/3640-18513_4-11673938.html?v=1