I use it. I feel it's a good place for storage of your ETH. However you might want to use something safer if the site faces an attack of some sort. I would recommend MetaMask in that case.
Yep, I recommend to use MetaMask too. Firstly I create and use wallet only on myetherwallet.com/. Then I registered one on MetaMask. It's easier to use, and also more safe. But then, when I tried connect my old wallet with MetaMask it says to me that first wallet is "loose". I don't know what it means, but think that it's not good.