Both wallets are doing the same thing and I think there isn't any difference of safety in both.But I'm using MyEtherWallet for months and I didn't see any problem in it.Therefore I don't have any need to switch to a different wallet.
To be honest MyCrypto is new to my eyes and never experience using it. IMHO, even there's a lot of hacking in MEW I prefer to still use it and I'll just be cautious in using this. Maybe I'll just ask my friends if they used MyCrypto and know their feedback and also I'll try to research its background and the team behind this wallet.