Since i am using mytherewallet, i have no problems about it yet. For me, it's the best online wallet you can use for your Ethereum Request for Comment (ERC-20) tokens because it's coming from the smart contract blockchain of Ethereum too.
I like that too. besides using myetherwallet is an easy thing. other than that, it's also very simple. So far, I feel that Myetherwallet is a pretty good wallet for storing eth platform coins.
myetherwallet is not a user friendly wallet compared to others out there and it isnt also safe because there are many people already lost thier coins after they used it .
im not against mew and infact i also used mew as a wallet for my altcoins but im only saying the truth based on my experience and on what i see online .
@op if you are really curious about your security , then youd better use hardware wallets that supports eth and erc20 coins because that is more secure than mew or any other online purse ..