How bad is it? It's a concert video released by Troma. Bad.
Should you see it? No. Unless you were there.
This has at least 2 sequels, but this first ones about the 2003 Vans Warped Tour. Almost no one in the bands or audience survived, apparently. There's a performance, then a killing, then a performance, then a killing (repeat ad nauseum). Lloyd Kaufman of Troma has a major role. The gore is very poor and done the same way each time. The music is... meh. There's surprisingly no nudity and very little nastiness for a bunch of self-proclaimed punks. The best I can say for it is that it looks like it was filmed by someone who had worked in film before this.