Decal or Plane model?

Which one is the best choice in terms of performance? I’m not quite sure if I should use decal or plane model to act as decal get better performance for an android game. I just use diffuse texture on my game old school style to be able to add more on game play rather than good graphics that gets boring the first 5 mins.

I think both are good…maybe testing each could be a good way to know what is better…the difference could be what complicated is the type of decal you are using…