I use a pair of Cateye EL500 LED headlights up to 20 mph on well lit suburban streets - much faster than the speeds reported on the spreadsheet. Still, I think the spreadsheet is good for relative comparisons between lights. There is one section of completely dark rural road where the EL500s also work fine, but on occasion I can have a little trouble seeing ahead when a car is passing by.
Planet Bike's Superspot is another LED light that uses 4 AA batteries, a feature I like. According to the spreadsheet, it is good for higher speeds than the EL500. Has anyone done a direct hands on comparison between the Superspot and the EL500?