| I have not tested any myself or know anyone that has tested them. But, everyone that has purchased them say they run as well as T-Hdrs, Pro-Pipes and D&D.
If you think about it, there are only so many ways to slice the pie. Every system is a compromise to some degree. Some emphasize mid range at the cost of top end. Some are designed for top end and sacrifice some low end. Some, like the Pro-Pipe tries to balance the two and get good performance across the RPM range. All 2-1 exhaust will exhibit some reversion. The amount of loss, RPM and range will vary from brand to brand but all will exhibit some.
Rinehart, V&H and D&D are all top quality products. | 
