In reply to Erik.

Hi Erik,
I came back to this article just to say thanks for letting me know about goodbyecaptcha!I gave it a try and… surprise!!!! After 2 weeks I've got ZERO/NONE/NADA/NULL/NIL spams. Unbelievable!!! Finally something that works! Better than any other plugin!
In case you guys want to install it: https://wordpress.org/plugins/goodbye-captcha/
Hope it helps,
Cheers!