The Holley system will also increase the idle when the AC comes on. I think FAST might do that also. They have a sensor wire that connects to the AC and when it gets a voltage signal the idle speed will increase.
Yes the Fast system does that as well.
I lot of the power comes from the infinitely adjustable timing curve.
I run the fast xfi system and needs a laptop to tune.
Being able to see what is happening is a big advantage. My car is a procharged street strip so the EFI made a lot of sense, at least for me.
There are both advantages and disadvantages There is a learning curve for sure
