I just installed the corsa cat back on my 21 6.2 High Country suburban. I have to say its phenomenal. I love the sound, which i was worried that it would be too loud. Its definitely loud at start up but really beautifull sound, and when your driving on the highway you dont notice to big of a difference. I did notice a performance increase with the corsa coming from GM performance cat back. I got the dual black tips. No fitment issues whatsoever. Definitely recommend. I ordered a rotofab cai which should arrive by the weekend. Hopefully i chose the right CAI, since there are multiple different brands i had to pick one that i saw the best feedback. I will update after i install it