Unfortunately, despite how interesting it is to see demos, most of the professional demos are paid for. Otherwise, why would they do it, unless they are musicians with financial stability and they just enjoy it...
I've seen Darkglass products jump to higher and higher prices. £400 for a distortion pedal is absolutely INSANE.
They have become 'the' distortion tone for more metal/heavier tones....and personally I think it just makes all basses sound very very similar. It sounds almost metallic and processed.
The craze is: fanned fret bass, shed loads of Darkglass distortion, normally some sort of dual pickup bass....then the bass riff almost sounds like a djent style guitar riff.
I still prefer Tech 21, if I'm honest.
Also, you can get a Helix Stomp and probably get exactly these tones or close and thousands more.