It is down. You have to use httpS to try the redemption site, without the s just forwards to paypal's main site.
Going away and turning off your site is such poor form. I discovered the outage myself today because I wanted to use a couple gcs and like you I just save the emails. I'll be printing them all to pdf right away from now on.
I left negative feedback on my eBay order already and suggest everyone do the same so PayPal digital gifts gets the message.