I'm surprised that so many people in the audio forum no nothing about techno.
The fast, heavy, 500-2,000 BPM songs aren't speedcore. That's extratone. Which I agree, can barely be classified as music.
Speedcore is generally 180-300 BPM. And it's very musical, unlike what most of you are saying. One of the best examples I can think of is DJ Sharpnel, who makes sone extremely high-quality speedcore/gabber. The duo is Japanese, so it's pretty hard to find their stuff. I have around 50 songs by them, and you'd be amazed at what experienced Speedcore artists can do.