I play on "normal", or whatever it is called in a certain game. I judge a game based on how balanced it is on that level. You might find it silly, but I find the very idea that the player should balance the game, not the designer, rather odd.
To me, that is one of the reasons why so many wargames have a simplistic AI, that doesn't put up much of a fight: those games often include ways to give bonuses to the AI, or penalties to the player, which to the designer somehow justified the mediocre performance of the actual AI.
If I would give myself 50% prestige, or the AI 150% or 200%, and some additional experience, it still doesn't make the actual AI better. At best, it gives it more to work with, but it can quickly feel quite artificial. For example, with more prestige the chance of a wall of units problem increases, where the AI places conscripts or some other cheap units around an objective so you can't take it on time.
Various penalties and bonuses also don't tackle the problem of having different campaign starting points, but just single scenarios regardless of the starting point.
WitE Alpha tester
Panzer Corps Beta tester
Unity of Command scenario designer