There's definitely a difference between a SR20 T28, the GT2860RS, and the 6758, with the disco potato have better transients than the T28 and the EFR6758 is even better than the other two while also being the highest HP supporting. I'm comparing the 3 on miata 1.8's with the T28 and GT2860RS on cast log manifolds and the BW on an equal length tubular.