I've had them all, old yozza, new yozza and miltek.
Tbh the miltek was the best fitment out of them all, literally stuck it on and didn't have to fart on adjusting it in the cut outs so it looked right.
Old yozza was a nightmare to sit right and the noise ended up embarressing.
The new yozza is the best out of the lot, loads quieter than the old yozza but a more purposeful noise than a miltek, I gained 6-7bhp from the old yozza to the new yozza on Rs tuning rolling road. I also saved 10kg weight from the miltek to the new yozza. I've got the dyno graph somewhere showing the difference between the two yozza exhausts