At least in my experience of my own lights and my friends' lights, you're going to have more problems with the cords and the connectors that you will with the bulbs on a Salvo HID. They are tough lights.
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Illumination V.S. Penetration...I think focusable HID's have the edge when in reduced vis. It seems LED's light up everything( including the cloudiness) whereas HID"s penetrate thru better.
The difference in the brightness is the DR 500 is 500 Lumens, the Salvo 12 Watt Led is 750 Lumens. So it will defiantly be brighter then the DR.