One thing CoH failed at, even somewhat with real numbers, was communicating to the player what X or Y buff/debuff/crowd control did in actual combat. Often a defense buff would only say it gave, say, 15% defense. Some players would easily make the misinterpretation that they'd only take 15% less damage, even though with mob mechanics, they took 30% less damage.

So what I am proposing, is that in addition to showing the numbers, also show what impact they'd have in use by themselves and in combination. I should not need a third party program to know for instance that my 45% defense would litterally mean only 5% attacks hit me. It should be communicated to me clearly how much a buff effect is having on me, or a debuff effect is having on a mob or even if it's applied to me.

It should be very clear in the power selection screen what does what and it's effects. City of heroes was very vague, as it didn't display the stats, or when it did, it didn't display the impact of some, defense and to-hit especially.

Some examples, we could have a mouse-over of the average chance for us to be hit based on our defenses, against X damage types, even warnings of defenses being weak in X or Y category. Or an average "it'll take x number of hits for mobs using y damage type to defeat you" for instance. Such scores should be easier to look at than in CoX.