As promised, here is my mini-review of the Shark exhaust on my 2021 GL1800 Bagger.
I was amazed to get the delivery so quickly - UPS delivered the parcel only three days after ordering (I am in the UK) So 10/10 for delivery time from California

First impression - They are nicely packed in a bespoke 'nest' style foam & cardboard box. After inspecting the exhausts I was a little disappointed to find that they are made from mild steel - I thought stainless was almost 'de rigueur' for aftermarket exhausts these days. That said, they are nicely painted in a tough black finish and the welding is first class.
One minus point - you don't get new exhaust clamps and your existing ones are too large so you will have to get yourself a pair of 46mm clamps or use an adaptor 'sleeve' (which is what I did)
Most of the holes seemed to line up quite well but a couple of the Allen bolts holding the shrouds to the silencers were a bit challenging, but a couple of my best swear words seemed to do the trick. 😁
Another minus point - the new silencers don't have the captive nuts on the hangers and you don't get the M8 nuts required to re-mount the silencers (no Biggie but worth noting)
After the installation it was time for a test run......
You definitely know there are six cylinders underneath you now! The tone is much deeper and a bit louder than I expected - not too loud around town but when you hit the open road and give it the beans ... WOW!! It will certainly take a bit of getting used to - I am not a fan of super-loud pipes but I like to be able to hear my revs rather than looking at the tacho. These appear to be a good compromise between tone & volume.
All in all I can definitely recommend these silencers - great value for money, even in mild steel.