Tried it, made no difference to any of my games, also installs unwanted programs too and tries to stop essential services.
Try it if you must but i wont be having it on my system.
Also the driver updater on it is useless, told me my Nvidia drivers were out of date when i have the latest installed.
If your games run well without it then do not install,
I never really trust these programs that say they can speed up your pc, any gamer worth his or her salt will know all the tweaks to do, without installing potentially risky software.