They only work great because you have not had to sue or be sued on them. For the same reason you don't buy a pair of pants that are one-size-fits-most, you should not rely on a contract to be a one-agreement-fits-most. Not only do laws vary from state to state, Nevada law changes each year. You will never have the best contract you can unless you have a lawyer drafting it specifically for you, paired with the knowledge of what you and your business needs. At minimum, you need a lawyer to review what you are using to make sure it complies with Nevada law, and update it for you at least every two years thereafter.