1. The idle speed increased from before install without touching anything.
This is mostly due to the Multi-Spark, if you burn (expand) more fuel your efficiency increases and in an unloaded condition this is seen as a raise in RPM
2. I can hold various RPM's above idle steady whereas before rpm would wander up and down and at times drop to idle in a very unstable way. Holding a steady rpm with the throttle was nearly impossible.
This is due to the stability (precision) of the spark placement and the above.
3. When accelerating you can very much feel that it's firing on all 4.
You will always see a greatly improved acceleration with the Ignition due to all aspects it's design, stability (precision) placement of the spark and it's ability to know the engines exact RPM during acceleration.
The exhaust sounds different
You will notice a much crisper sharp tones from the cylinders as you are expanding more fuel and exhausting it much more effectively. If you expand more fuel during the power stroke of the engine the cylinder will run much cooler, the expanded fuel presses down on the piston more and you get torque. If you don't burn (expand) all the fuel you can by 40° ATDC you have wasted it, going out the exhaust still hot and burning. i. e. To retarded a timing turns you pipes blue. Once the piston passes approximately 40° ATDC the piston speed has exceeded the speed of the expanding gases and no longer pushes the piston downward.
How it helps the exhaust:
The exhaust valve opens a approximately 30° before BTDC, the expanded and still expanding exhaust gases actually push out the now open exhaust valve and you will expel as much as 50% of the exhaust in what is still classified as the power stroke. The more gas you expand the more you will exhaust in the portion of the engine cycle and relieve a great amount of engine power loss on the true exhaust cycle.
The sad thing is no one has asked questions as to how the Ignition really works and why, how such things as load (wind shear, side cars, gearing, weight, grade), octane, acceleration and many other things effect timing or how timing effects them. (you think going from 4th gear to 5th gear at 70 mph and accelerating might be a load?) How Multi-Spark really works and its effect on quench, squish or standoff and why it is beneficial to reduce lean and rich misfires. Why is ignition stability important, its just a spark. Why is the coil and wires such an intricate part of the ignition system? How you can utilize the 4 timing maps (curves) that come with the ignition and why they are there. What is a VOES or Map Sensor and how can it be used? Can I change the curves on the fly?
Comment on load: Tell ya what I live on the farm and have a cow catcher and the front of you truck, you stand on it with a 4X8 sheet of plywood and I will pull it up to 100 and see when you look like a bug on my windshield. Very similar to what you have with a GW.
The thing I have noticed it have no matter what the engines problems it always ran better with the ignition. Once you find out how well it can really run you may want to clean that carb or fix that vacuum leak.