if you go with a full standalone ECU like the microtech or EMS, you will loose full control of the VVTi. There's only a couple of aftermarket standalone ECU's out there that can control it correctly, and they are quite expensive (eg Motec). With the piggyback ECU's the stock ECU still controls the VVTi so that's all good, but they're still just piggyback ecu's modifying the stock ECU's input and output. The emanage works well on the 1ZZ, and has been used with quite a bit of success on 1ZZ turbo installs in the US. It has more features than the Unichip, and gives you the flexibility of not requiring an "Unichip Authorised" workshop who have paid for the unichip software to tune it. There is a new version of the emanage being released soon which has even more features than the current unit, I'll be getting my hands on one to see what it can do when it's released.