The TRD unit is certainly good value considering the gains. Believe me I've done the sums and research on it. It's quite well thought out, being designed to bolt on and operate with all existing engine ancilaries. It replaces the existing inlet plenum and the fifth injector is a nice touch both ensuring the engine doesn't lean out at high rpm and also giving a cooling effect to the engine. And there's alot of users in the US who run it reliably with no problems to talk of, in fact, they seem to have a preference to supercharging 1zz's rather than buying 2zz's. Only thing is, Unlike in the US there's no support here at all for it, once you have it, you're on your own and I certainly wouldn't want to take that risk. The ECU they sell with it in the US isn't suitable for the AUS spec rolla, so that's why Danz said just purchase without ECU.