Considering upgrading to 1.71 but have a question about spam protection

I was thinking of upgrading my little Elgg site from 1.61 to 1.71 but have a question about site security. Really about spam protection.

WIth the siteaccess plugin I can block people from joining without an invitation. Without something of that sort, my site gets like 10 spammers a day - a nuisance to delete afterwards.

Is there something core to 1.71 that helps block spammers from joining? I hear siteaccess doesn't work yet in 1.71.