I received the HKS Spec L exhaust a week or so ago. Just got it installed this afternoon. Sounded pretty good, I'm really happy with it! I haven't done a video inside yet but hopefully I remember to do so soon. There wasn't any drone when the windows were closed and I think there was slight drone windows down... I didn't get to drive much today though but I'll report back after some time if anyone's curious.
Oh yeah, one of the tips arrived slightly bent so I'll try to see if i can get that replaced somehow.