My suggestion will always be Corsa if available for your purpose. That will be what I go with if I ever mod the exhaust on my EXT. Had a Kooks header and Corsa catback setup on an LS1 Formula that sounded incredible. NO DRONE at cruising!
i had an 08 esv with mbrp cat back and it sounded amazing. For the money I felt like it couldn't be beat. I just bought a 13 ext and was going to go with a mbrp cat back again but for some reason there isn't one for that year ext but there is one for a 2010. yall have any idea why? i'm going with mbrp this go around again.
I'm going to go with magnaflow. I had one out on my recommendation of my muffler guy who's done all my cars. It was a good compromise between rumble and luxury. I didn't want an all out get out of my way sound. To me it gave it the perfect gravely deep growl.
My EXT has the GM Performance Exhaust. It sounds fantastic. Nice deep rumble under heavy load, quiet highway cruising no drone whatsoever. Nice bark on start up. I honestly can't imagine a different exhaust sounding better. But I'm biased. Also looks fantastic with the large chrome tip. Worth looking into. Cheers.
I had a corsica on my 2005. It sounded great. I installed a dougs electric cut out on my 2010 after I bought it. Sounds good as well. It was a fraction of the cost. I also had the cutouts on my 2010 cts-v both are great chouses. I can run it open or stock at any time