[jluetjen]

I think of throttle response this way:

If you think about moving the throttle and the car sounds like it is starting to accelerate and it feels like it is picking up. That is great throttle response. MFI's provide this experience.

If you move the throttle and the car responds by accelerating. Then this is normal throttle response and what you will find with CIS 911's and most cars on the road today. Once it starts to accelerate, it might pull like a train, but that is HP and Torque as opposed to throttle response.

If you have to plan ahead to ensure that the engine starts pulling when you want it to accelerate out of the apex of a corner, then this is "Turbo lag" or poor throttle response.

I'm not sure that I agree that big throttle bodies and space cams have a lot to do with throttle response. I think that it has a lot more to do with fuel delivery as soon as the throttle is moved. MFI's have it because they are pre-mapped and moving the throttle immediately moves it to the new point on the map. Instant Fuel!. Webers are close because their accelerator pumps give an extra squirt of fuel. CIS and other closed loop injections systems don't have instant throttle response because they need to wait for the air column in the intake system and plenum chamber to move the sensor plate which then meters out more fuel. Turbos have a lag because it takes time for the turbo to spool up.