The face is just personal preference I'm pretty sure, I wanted mine all black but there are a lot more with the white faces available (the gauge cluster face is white in the SLK so the heater matched) The big thing to look out for is really the back side of the unit. You can see part of it on the previous page with mine side by side. The xfire unit has a large back piece that the wire harness plugs into and the arms are able to swivel at the base. The MB unit I have has the plug right on the back and the arms are solid. As stated before, mine works but if you can find one that is more like the xfire style in the back it would prob be a better choice. I might have some pics if needed but the difference is pretty obvious when looking down from the top, the xfire unit is way deeper and you can see the hole for the connector.