I think the Edelux probably wins the high speed rural riding crown. Just because you are throwing light everywhere doesn't mean you can see better. The three lights I would consider for this are the Supernova asymmetric, Edelux, and Cyo (60 lux version). These lights don't put out as many lumens, but they put it where you need it for road riding. Sometimes on really high speed turns I have to apex early to get the light where I want it with my Supernova, but I'm not sure that isn't the case with most lights. A helmet light in addition to the headlight really makes sense for that kind of riding.

I have done high speed descents with my Supernova E3 Assymentric and was really happy with it. I had a home built triple with more lumens before, and I couldn't see half the time