firstly, i use both for finding info about coin and exchange. but, as we all know, CMC now is acquired by binance. just be careful for exchange that use fake volume, they are working on it right now!
as CZ said on his tweet "The fake volume exchanges can't keep up with their fake volumes in volatile markets. A tell-tale sign.
Yes, I did pass your feedback to the @CoinMarketCap team. They are working on it."
https://twitter.com/cz_binance/status/1255583607290073088