I will try to record a few videos over the weekend of just the rear section paired with the stock x-pipe. So far I'm extremely happy with the Challenge exhaust. I haven't heard anything else in person that has such a good balance of sound, no drone, build quality and price.
Once alpha///m installs his setup paired with the sport x-pipe, we can try to do a side by side comparison with my rear section only.
Current: B8 RS5 Sold: F80 M3 - 6MT / 981 Cayman S - 6MT