Without a doubt, having to still co-parent with a person whom you seldom agreed with to start with. It's frustrating having your "discipline" undone, or your values not mirrored by the other parent. I know I'm making a lot of assumptions here, but I don't think you'd be considering divorce if you and your husband agreed on these core things.
It really does come down to the struggle you have wishing you could insulate your children from the inconsistencies that they will now experience because neither of you will have to yield to the other, any longer and you'll both frustrate the heck out of one another, with the kids squarely caught in the middle and having to figure out which parent's style suits him or her best.
Kids are resilient and believe it or not their experience will teach them an awful lot about how to confront inconsistencies and differences in life, in general, but they will feel torn and conflicted regarding which parent they should trust and be loyal to and I don't think there is any way to avoid this conflict within them.