It will remain safe as long as we take a very carefull actions to our mew wallet. Never make a mistake by submitting our private keys to someone else and make sure we only visiting the correct mew site.
Technically if our device is safe then MEW is quite comfortable in use because all also return to ourselves each how they care for devices that are used to access the wallet, I until today still use MEW despite a lot of threats hacking but if we careful in opening the site it will remain safe, especially we have long used the wallet and I think to distinguish MEW official web is very easy.