Different style pipes give types of performance. A long narrow pipe will give you RPM performance a short fat pipe will give you Torque performance. Basically the RPM pipe will use the high end RPMs of the engine and produce power there, the Torque pipe will use the end(take off) rpms of the engine to produce power in the low range of the engines RPM. SO it depends on where youw ant to get your power from. THe stock exhaust is a great midrange exhaust that uses pretty much the full range of the engines RPMs