This used to work really well, but now I just get the spinning beach ball of death at some point during upload and have to force quit (OS X 10.4.11). Even worse, the email sends before the file has uploaded, leaving multiple recipients with a useless pando file in their inbox (in my case twice, as I tried to resend after restarting the MacBook, only to experience the same problem).

The final nail in the coffin is that the latest Windows installer can't seem to access the Pando servers to install itself in certain IT firewall configurations, making it unnecessarily difficult for PC users to install it.