Microtech is designed with race vehicles in mind. Race cars don't need to run closed loop because they're on full throttle all the time. They don't need a lot of resolution, because they're on full throttle all the time. If you're a dragger and max hp is your concern, then Microtech is the EMS for you.
If you're into track racing and fast road, then you want a Haltech. Its more expensive but it has double or more resolution of the Microtech, for more precise tuning on part-throttle applicatins. It runs closed-loop to save fuel on cruise for street use.
At the end of the day, it's the tuner that makes all the difference. So don't flame me saying "I install Haltect but my engine is suck and veli yumseng petrol but still no power"