Metamask is easier to manage multiple accounts transaction in simple clicks.
If you are with Ethereum only transaction, coinbase can be easy.
There are private key associated with every wallet address, you can easily manually use them to operate multiple accounts from myetherwallet.
Metamask lets me create only one address. Or did I miss the function to create more?
I read that multiple addresses are possible in combination with Ledger Nano S. Is this right?