I've used both coconut cream and coconut milk. The difference in the two boils down to a ratio of coconut flesh/fat:coconut water, which is chosen by the manufacturer. Coconut flesh/fat will add to your superfat - however, if you are using it in CP, you cannot control whether it's the fat in the coconut cream or the rest of our oils contributing to the superfat in the finished bar, as the fat content in coconut cream is susceptible to saponification. Coconut water will boost lather on account of its sugars.
I quite like both, but find that coconut cream will contribute to a softer, rubberier soap on account of the superfatting issue. Coconut milk is more likely to boost later without significantly affecting superfat. Coconut cream soaps are definitely "creamier", and have a bit of a lather boost. Coconut milk is less "creamy", and have a lot of lather boost.
Neither additive will contribute to any delicious coconut smell in the finished product, unfortunately.
