Coinlib I think works better for me, I got introduced to it by a friend and so far I have been enjoying it to watch my portfolio, Coinmarketcap takes time before updating coins but coinlib updates as soon as a coin is trading in an exchange
For my opinion, CoinRanker has simple GUI so it fast loading, i don't see much different features from this both exchanges, so far i know every those webs has showing little different on price and market volume datas.