This is one of the best masks for accessing the etherium wallet, since you have your private keys and you are responsible for the data and transactions made, everything is managed in a decentralized manner.
Your code is open for verification, and totally free, this mostly to the commitment of the community that supports MEW.
As for its use it depends on your needs, since just creating the wallet is extremely simple and the standard security methods,
Access method, compatible with multiple devices and extensions which make it easier to use, for example MetaMask and hardware.
And most importantly for some, it protects the privates since it does not record data and information of the users, its mobile application is ideal for really versatile P2P payments in its use and fast.
Its main problem is its use in less experienced users, especially in that the application is not intuitive and should read the user guides, By the way this seems correct since MEW has enough information not to make mistakes.
In general whenever I can recommend this wallet to people who are going to use Etherium and the tokens of this platform since it is a relatively easy way to use this combined for example with its APP and Metamask. Having a good security keeping our data private.