This tiny little guy is the kind of addition to a rig which makes a huge difference.
As your audio signal travels through long cables, pedals, patch cables etc it becomes tired and looses the initial punch.
This is why we hear people saying things such as “the best tone is the guitar straight into the amp” ……… well ……. not with this baby.
Do you need a buffer?
If you have all true bypass switching on your pedals, if you have very long cable runs, if you have no buffered pedals in your signal chain then yes.