Why not? To my mind it is safiest site, but you have to bookmark original pagein order to enter your data on a right website.
2-3 times there has happened issues with DNS changing,but it is rare
Also I can advise you to use the antivirus to check the site's license. If you use Google Chrome, you can install the application Cryptonite by MetaCert. It will protect you from phishing scams and fake twitter accounts. If you are careful, the use of the MEW will be safe. In my opinion, this is safer than using wallets from third-party developers.