I set up a special sale page for a pdf version of my product.
Set the restrictions page to add the id of the download page for the pdf product
generated a paypal button using S2
tested the paypal button and it showed the correct product
did not do a test purchase to see if the redirect came back to the pdf download page
On the download page, I had inserted a link to the pdf book which was in the s2 member download folder.
S2 changed the pdf download link to another product in the folder which required an activation key to unlock it.
When the S2 Member plugin is deactived and I try a browser access to the pdf download page, I am redirected to the Membership options page.
I would think with S2 deactivated that S2 redirects would not work.