I detest labeling children. One of the terms I dislike the most is "strong willed child" because of the negative connotations it brings with it. It is never said it in a positive way and is often an excuse for a poorly behaved child.
There are some children who do exert more will than others. It may take them longer to come around to a new idea. They may 'rebel' against everything you say at first. However, being negative about it and giving them a label of "strong will" is not going to help them.
God created each of us with different personalities. How boring it would be if we were all the same! I have 2 children who would be labeled 'strong willed' if I believed in such a thing. Instead, I believe in viewing their will as a gift God has given them. Think of the people in the Bible who were strong willed and what awesome things they did for God!
While a stronger will may be more difficult for parents, it is better to embrace that will. They are still teachable, you just need to learn what helps your child to overcome the negative aspects of his strong will and embrace the positives. Humor works for both of my children who struggle with this. Also spending quality time with them and keeping up a fairly consistent routine helps when they are younger.