This occured to me recently - wouldn't it make a lot of sense to lower the threshold to 50% for a successful undeletion of speedies? I'm all for keeping the 75% threshold for stuff deleted via *fd, since *fd deletions require consensus to achieve, it makes sense to require a high standard to overturn that decision, however if an article has been speedied (ie the deletion judgment was made by one admin, rather than a discussion on *fd), and 60% of people think that it shouldn't have been, surely there is something wrong there.
Sure, I know that voting is evil, Wikipedia is not a democracy and so on, but shouldn't speedies (or, to be more precise, an individual admin's interpretation of whether a page meets the speedy deletion criteria) which are not subject to any community scrutiny be easier to overturn than *fd votes, which are?
Cynical