The area around the festival isn't that nice. Much better off staying closer to the city centre. Getting there is only a metro journey. They put on extra busses too.
I'm more practical like. I'd think it would better to be closer to the venue (so if during it you need to run back to your place to get something, nap, change or use the bathroom -- being a girl it could sometimes be quicker to leave than queue) than to the city centre.*
Not that I'm going but I'm still kinda hoping to.