[Suicide Junkie]

Because that limits you to having only 2 bonuses. Or, you have to limit them to 1 of 2 categories that add together to get the multiplicative value. Which again, is more limiting than the current system. Also, what is 1.0 / 1.2? 0.833. Now, the 20% ECM penalty has dropped to 16.7% (or .167).

What are you talking about?
If you want many bonuses and penalties, you just keep multiplying or dividing. I don't see the problem here.

And, come on now. You wanted the so called "20% ECM" description to mean that it cancels a "20% CS"
Now you're complaining that the effect isn't exactly 20% when the combat sensors are not involved?
Diminishing returns are part of the point of using multiplication!