Electrum is more lightweight but it does not offer ♯♯ wallet file security.
This part is not right. Electrum uses AES-256-CBC which is, to my knowledge, a pretty strong way of encrypting the wallet file for security.
I agree with this user.
He is wrong. AES-256-CBC is used in many wallets. So no difference between them. Look at multibit hd beta 0.5 any why it is early. It uses AES-256-CBC and scrypt for key-stretching. Electrum uses SHA256d for key-stretching, same as mining. In this picture you can see brute force attacks with a normal computer. All the wallets use AES-256-CBC. The question is about offline computer. Is encryption important when offline?
https://imgur.com/b59utxl (if it does not load, click)