If I untick that, then sure... JSON with encrypted keystore entries:
This was switched on by default since 2.8 apparently: http://docs.electrum.org/en/latest/faq.html#how-is-the-wallet-encrypted
You can tell which setup you have based on whether or not Electrum asks for a password when you first start it up (or open a wallet). If it asks for the passphrase, the wallet file is encrypted, so it needs the passphrase to open and read it and load your addresses/transactions. If it just opens up and displays all your transactions etc and only needs a password to send or sign messages etc, then the wallet file itself is unencrypted (but obviously your keystore is still encrypted)
Yes, I forgot about that. If you leave the password blank when creating a wallet in 2.8 you get an unencrypted wallet file. I have been leaving the password fields blank in my personal wallets, so the change to whole wallet file encryption slipped my mind.
However, a bitcoin core wallet.dat is still in a completely different format to an electrum wallet.