Consider an alternative version of confusion: it lasts for 1 round per caster level, no matter what. On each round, the target must make a Will save; if he fails the save, he's confused for that round.
It's clear that my alternative has the same expected number of rounds of confusion as the original. It's also clear that the variance in the expected number of rounds of confusion is a lot lower. (I actually have to handwave to make that argument, but I think that the variance of the original is proportional to the caster level, and the variance of the alternative is proportional to the square root of the caster level.)
But it's not clear to me how that would change the strategy or play of the game.
It'd requre a lot more saving throw rolls, certainly. By reducing the variance, it would make the character's saving throw modifiers have more of an impact compared to luck than they do currently. This would probably favor PCs, because PCs tend to have better bonuses than their opposition.
I solicit comment from those more experienced with D&D on other ways this might change things.
Another style of spell would be like that for hold person or greater command, which give saving throws every turn. Under this style, confusion might operate as "make a saving throw every turn; once you succeed on a saving throw, you are no longer confused." This clearly has a much lower expected number of rounds of confusion. (You could fiddle with the save DCs, or even have a decreasing save DC, to adjust the expected number of rounds--but that would involve more work.) This would clearly favor characters with better modifiers quite a lot.
Much to ponder here.