I came across this several days ago and hence I made my statement. Bitcoin Core does have a more advanced encryption [1] and more than AES-256-CBC.
How old is this?
Probably fairly new, it was uploaded on Aug 1 anyway and it has appeared on the forum quite sometime ago.
How strong or weak was the passwords which were used? (the length of the password for example was it "123" or was it "2Fd#4dlR&jfh8"?
Doesn't really matter. The results showed the number of keys tested per second and not the time it takes to crack them.
Although I have to agree that Electrum is quite secure, I have to say that Bitcoin Core, Multibit etc is harder to bruteforce as compared to Electrum. It wouldn't be a problem if you're using a long and strong password. It is a problem if you are making a cold storage and someone else have access to your encrypted wallet files anyway.
[1]
https://en.bitcoin.it/wiki/Wallet_encryption