Yeah, Borla cost some bucks. There are 2 versions of the XR1, the Multicore & the Sportsman. The Multicore as the name states had individual tubes encased and cost a hella lot of money. The Sportsman has an oval tube inside a perforated tube and is relatively cheap.
I have read that Borla makes nearly perfect mufflers in that you loose no HP with them installed. Same with Flowmaster, the 10 Series is what they called "the perfect muffler design" because it doesn't intrude on the engine at all. I'm going to keep asking questions and researching the XR1 Multicore, I want them.
Exhaust testing results article below
: Auto Exhaust Science