"As an owner of a Borla exhaust-system when I owned the RX-8, I can honestly tell you there is a reason the exhaust is so expensive. It's WORTH IT. The quality of the exhaust was the best I have ever seen, and it was built like a rock. The thing was tough and sturdy. They are tested and usually include flow characteristics and dyno charts as well. Then you get into the sound portion. It's beautiful. It sounds fantastic, and you don't have any drone on the highway. It's loud when you want it to be, but when you're off the loud pedal it's as if the car doesn't even have an exhaust system. Think WS2 quiet when you're off the gas, and DC Sports loud when you're on the gas. The perfect combination, and something you DON'T get with the Skunk2, Apexi N1, DC Sports, Invidia, etc. You get loud when you're on the gas and loud when you're off the gas with those. The exhaust is also typically lighter than the factory exhaust system as well which was a huge bonus for RX-8 owners. A lot of R&D goes into their products before they are released, and they are well-worth the cash. I plan on buying one for my Si, that's for damn sure."