Pepperdine will increase your scholarship if you do well in the first year. I would say go to Pepperdine. I may be a little bias, but I personally love it at Pepperdine. Also frankly I just don't think you will have the same opportunities at Chapman that you will have at Pepperdine. If you have any more questions about Pepperdine I would be more than willing to answer them, but I definitely think you should choose Pepperdine. I don't know where you are planning to practice, but Pepperdine does have a better reputation in Southern California, and if you want to practice out of California you would be much better off going to Pepperdine because most people from out of state have not even heard of Chapman.
Also you may want to check with your Chapman scholarship what the class rank is for having a 3.0 because just because a 3.0 sounds like an easy GPA to get in undergrad, does not mean that that GPA would be as easy to get in law school and it may work out that getting a 3.0 is the same as being in the top third at Chapman.