So, my opinion on this exhaust. Other than the minor fitment issues, it's a good pipe. If it is a cat, it doesn't seem to hamper the performance at all, even on my big bore, ported, cammed CG250. The larger pipe volume after the "cat" likely helps with that a little bit. What you gain is a better fitting exhaust system, with engine, frame, and airbox clearance as well as the ability to fit any 51mm inlet muffler your heart desires.
As for me, I just ordered this guy iin the 440mm length because it was less than 40 bucks with a "coupon" deal:
https://www.aliexpress.us/item/32568...yAdapt=glo2usa
I also ordered this inlet baffle. I may not need it, but I really like the design of tit, and it as $5, so why not.
https://www.aliexpress.us/item/32568...yAdapt=glo2usa
It lookslike it will do the job without being as restrictive as the other one I have. My main goal is to have the performance of an exhaust system, but without as much noise as the normal ebay system. I want to be a little less conspicuous... or I am just getting old.