Depends where. My personal opinion is that I don't really like Kempo that much. Besides, Chinese/Japanese Kempo are pretty much the same thing, they both come from Chinese techniques. What might seem good is that it takes movements out of chinese gong fu (shaolin, and simplifies it. But what I don't like is its missing ALOT of important elements that make Shaolin Gong Fu what it is. When searching for MA's, I always prefer finding a good teacher, and the original methods that inspired, and were the root of these modern arts.
The original Kempo guys from what I understand were pretty tough. But nowdays, Kempo schools seem highly disullisioned. Of course this is just my opinion. Alot of schools that pass themselves off as Shaolin (Shaolin Do), are actually mediocre Kempo. So do your research.
Truth comes from the absolute stillness of the mind...