Well the new OVXs have the new hinge style that is so pose to be less breakable but then again mine (its the new style) broke after two years If I had to take a guess they don't last as long since Cooper ballasts seem to crappier and crappier
I notice the older OVX had that angle on the back of the housing, while the new design doesn't. The one with the angle is more like the OVS or OVM, as both of those had the angle on the back, but now the OVX's took those off. I would say the older OVX has the more classic look... But the new one is better designed.