On a site I'm working on, The homepage has generic content for visitors who aren't logged in. When a user is logged in, the content shown is personalized to them and could even be considered private.
So when a user is not logged in:
<meta name="robots" content="index, follow">
When a user is logged in:
<meta name="robots" content="noindex, nofollow">
Since both URLs are the same, are there any SEO concerns since the robots directives are different? Is it better to send the user to a different URL for their personalized homepage, and why?