This small and cheap pedal is a really mighty one!
You can go from clean boost to sweet solid Klon-overdrive.
When I play a solid-state amp, I use it as a always-on pedal because it gives me the dynamic of a valve: light attack makes it clean, digging in, makes it "break".
When I use my valve-amp, a Orange Rocker Terror 15, I use it to push the amp in the most amazing way.
Is hard to explain but having this pedal on just makes your tone better: fuller, sweeter, richer but not in a overwhelming way.
The only downside might be the "Volume" knob: is very sensitive. You can get insane volume from this pedal, so is very important that you dial the right amount.
The bottom line: buy it, plug it in, and play. You will feel happy.