I'm guessing that using PHP's header("location: here.html") would be much better javascript's window.location("here.html") as far as search engine visibility goes. I would assume that the server redirect would show google the correct content and the javascript redirect would be read as a page with the javascript redirect code in it.
Reason being is I have a client that wants me to take their current website and import it into a CMS system (I'm using e107) and I don't want their old pages to lose their current page rank. I was thinking of putting redirects on the old pages to the new pages in the CMS system.