My checkout experience:

Enabled the button, clicked it, nothing happened. Looked in Firebug at the Network console, saw a failure come back from the 'Pay' step.

Triple-checked my payment info, clicked the button once more. 25-30 seconds later, I got two consecutive "Something went wrong" javascript alerts. A minute or so later, I got two confirmation emails, lacking any useful details. I'm guessing I was charged twice.

Once it is possible to log into the site, I will see what my order status says. Right now /login continues to time-out.