I don't get actual spam in gmail, but I get occasional bounced messages when spammers try to send email with my address in from field. Even google groups would bounce back the email I never sent. I even got spf/dkim for domain, yet they still inform me they couldn't deliver a message I never sent.
I get the occasional bit of spam in my inbox, but it is not nearly as bad as it used to be. A bit of client side spam filtering coupled with Google's filter is good enough.