This looks really good, but I'm always suspicious of extraordinary benchmarks with no explanations. What about sift makes it so much faster, than, say, ag? Ag already seemed to be decently optimized, so I'd be interested to know what the breakthrough is.
"a fast and powerful"... Couldn't you find a better naming? All newly tools, languages, etc... are: "fast, powerful, robust", but at the end of the day, it still sucks.