I think Vectis was on about how you put Halegen instead of Halogen.
I don't know about the 2.0's but with the earlier model I found having it on for more than 45 minutes would blow the lamp because the lamp seemed too higher a wattage for a casing that size and the cooling fans were not good enough.
I wouldn't use them again, I think going by how many people on here use Dynamo's that they must be the better buy.