In most cases, more choice is usually better for the consumer. If BB can produce a top quality product, specifically designed for the v10 S6, with proven results, at a competitive price, then I am sure they will have some customers.
However, I wouldn’t buy one from them, because they are not Audi v10 S6 experts. If I am going to spend thousands on an exhaust, I will only buy something that is specifically designed for the car, and made to work with a total power package (e.g. catback, headers, ECU tune, TCU tune, intake). There are only a couple options for the v10 S6, and there is a reason… Very few people really understand the car, and the market for v10 S6 aftermarket performance parts is minuscule.
The Milltek catback is a perfect example. Here is the v10 S6 Milltek exhaust
http://dfklk0jrz9g9k.cloudfront.net/images/custom/509.jpg
And here is the C6 A6 4.2 exhaust
http://dfklk0jrz9g9k.cloudfront.net/images/custom/514.jpg
Look familiar?
Both are Pipe Ø: 2.36" (60.00mm)
All Milltek changed for the v10 S6 was the tips and part where the catback connects to the stock exhaust.
How is it possible that the ideal design for a v8 4.2 exhaust is the same as the ideal design for the v10 5.2?
Of course, the answer is that is can’t be. Milltek charges over $2k for an exhaust that is just a slightly modified version of the 4.2 exhaust, which can be found online for $1200. That is how these companies make money. They do as little research and development, and retooling, as possible, when releasing a new product.
Any great exhaust shop can build you a nice looking exhaust for your v10. However, there is only one team worldwide that I would trust in building me an exhaust that is specifically designed for the v10 S6, and made to build the most power. And obviously, that is who my money is going to.
Options are great, as long as you are making an educated decision. Dont fall into the trap of wasting thousands of dollars on something that just looks nice, and sounds good. If all you want is a louder sound, then just delete your resonators and call it a day.
Regarding the Viper exhaust/headers, you will never be able to get v10 S6 headers for that price, with a quality build, designed to make optimum power. Those guys will sell 100 sets of the Viper headers before we will sell one pair, for the v10 S6. If you get me an order for 100 v10 S6 headers, then Ill find a way to slash prices too 
Also, it is about quality of parts and materials. The HJS cats I use in my exhaust would normally cost about half of what they are charging for a complete headers/exhaust. You get what you pay for (although I am sure some lower cost cats are fine, but might not last as long as HJS, or flow as well)
Remember, the aftermarket has had 8 years to design parts that build power for the v10 S6, and they have really offered nothing substantial. I know everyone around here is getting excited with the recent developments, but I just want to remind people, don’t lose focus on why everyone is here in the first place. The v10 experts are on this forum, and no where else. They are building parts to make power for the car, where everyone else has failed, or ceased to even try.
Cheaper is not always better. Do your homework and then place your bets 