Coinbase is perfect competitor for blockchain. Most of the both these wallet fees and usge specification all would be same but from the past 6 months Coinbase team working better than blockchain and their fees also little lower always than blockchain.
You will be able add the multiple addresses only in blockchain but coinbase would give multiple wallets in one email signed up. Re Ven time BTG hard fork also coinbase team provides the support notice to all their wallet users. So it is being always ahead.