Like I said, its legacy has mainly been the laws and powers that were drawn up specifically to combat the terror of "music partly or wholly characterised by repetitive beats". Those laws continue to be used today, to subjugate otherwise lawful assemblies of people whose only crime is to be playing music.
Article technorich posted is great. This:
It hasn't been a particular positive legacy, but its been an important one - raves redefined the relationship between the police and the public.Fifteen years on, there is little pleasure to be gained from saying "we told you so". But the manner in which a law designed to prevent the wholesale mayhem of Castlemorton can now be used to foreclose a birthday party should serve as a stark warning to those currently considering a raft of other illiberal legislation, from the coroners and justice bill to the various ID card proposals. Those who deride the contributors to liberty central when they warn about the incessant creep of police powers, or who scoff at "slippery slope" arguments around civil liberties, should bear in mind that we stood at the top of one of those slopes only 15 short years ago, and we have slid a long way down it since.