I'm getting a redback catback tomorrow for my xr, just wondering if they sound any good before I get one so I can back out if I need to.
I want loud with a bit of grunt

I have a single 3" redback muffler on my 5.0 NF and it sounds great!

Buy for performance, not sound.
A nice sound is usually a bi-product of performance

I suppose I should mention that people who know cars, will know if you have a noisy exhaust that cant perform. You wont be fooling many people, and you will draw a lot of unwanted attention. (from the filth)
Noise alone can be made with wacking on a stupid assed cannon muffler on the back with a 2" in and a 4" out and the whole thing acts like one great homosexual trumpet. Decreeing to everyone within 3 city blocks that there is a boy racer with a crap car in the area. Such nonsense makes me want to alight my car and brutally bludgeon these drivers to death with my forehead. Please dont buy a cannon. EVER.

I think you will get a slight performance increase, as well as a bit more economy if driven steady and the engine note which is balanced and not at all too wanky.

As for what you're going to pay for it. Check this out.

http://www.ebay.com.au/itm/Falcon-EA-EB ... 135&_uhb=1

There are second hand 3" about for $300 too.

For your consideration.

ps. you didnt mention 8 or 6

I love my BF turbo exhaust on my BF Ghia. Really nice sound, but not too loud, and no drone.

Those aftermarket exhausts are too loud and wankish for me. I'm not 20 anymore.

Performance > sound.