I've used the PLX wideband. It worked fine and was a great deal. It had no gauge or display though, we used the wideband voltage output fed directly into a TEC3 unit. I've also used Techedge, AEM, Horiba, and FJO, and they all use the same Bosch sensor except Horiba which uses the expensive NTK. Accuracy is dependent on the sensor so all the controllers never made a difference to me.