I've flown both in business and I'd say the service is similar. But I avoid CDG whenever possible. I have had nothing but bad luck whether departing or connecting at the airport. AMS is such a breeze to move through that I never worry about issues there.
My vote is KLM...plus you get a miniature house! Doesn't mean much to me personally, but my wife enjoys them and we all know the saying...'Happy wife, happy life.'