I just installed a Borla S-Type II axleback exhaust on my 12 Coupe. It finally sounds like a Corvette should- throaty rumble but not overpowering, like the ATAK might have been. Others who have purchased the Borla Touring stated that it was not really enough of a bump from stock. The S Type-II is kind of the mid-point of the Borla family.
My installer, who is a BB retailer and a speed shop owner, said that he thought the Borla actually sounded better than the Corsa's. Throatier growl than Corsa's. Both tech's offered the same opinion.
So far, I like the addition of this system to my car.
I can personally vouch for Borla's awesome Customer Service and Warranty protection. My retailer shipped my Borla system and a part was damaged in shipping due to rough handling by the shipper. The retailer had the Borla factory rep on the line in a three way conference call within five minutes and the new part was shipped the next day. The Borla folks could not have been more accommodating and responsive. I had heard this about their Customer Service and their Million Mile Warranty Protection.
Did I mention the price difference in the two brands ? Using my online supplier as an example, the Corsa generally runs about 15-20% higher depending upon which exhaust system you purchase. It is just one more metric to factor in when deciding upon the purchase. I do not think you can make a bad decision by choosing either of the companies products but the price difference factored into my decision as well as acoustic performance and warranty protection and support. YMMV