These two coins are quite good but different, I definitely choose Ethereum is a fairly stable currency just now is starting to raise its price. It is also perfect to invest and maintain for a long term and in this way obtain large profits.
Actually, the two coins have the same strong potential, and both also have platforms and wallets for each coin, if in terms of transactions are similar, maybe ETHs are more popular because they have a wallet that is very easy to use and many projects that use platforms under Ethereum, but for investment I am more likely to choose both because both coins have strong potential in the future.