They are about as different as you can get style wise with Shotokan as you know being more of the traditional Japanese school and Kenpo well, not being so traditionally rooted. As Wastelander states you will benefit from some of the things they do in kenpo, but I say that as a long time believer in training in many different styles to become a more rounded practicioner. Whether it is for you or not, only you can decide, but give it a try. What have you to lose?