Just saw this thread; I've been testing an R&D Aquavein vs Riva toploader on my 07 RXT. Swapped repeatedly at the lake and ran them then went to the bay in the rough and did the same. Repeatable 1 MPH increase with the Riva; both stayed hooked up up well in the chop vs the stock. Neither are way better than the stock grate for speed but definitely stay hooked up better. I'm keeping the RIVA...helps reduce the number of load/unload cycles on the supercharger clutch when riding hard in the chop. I got this grate from another 07 RXT that runs solid 76 (Fizzle external intercooler, 4" kaneflex intake, prop work, pump wedge, OPAS delete, remap, resonator delete, injectors, supercharger upgrade, etc.).