My mid-2012 MacBook Pro is worse at waking up from sleep than I am. I mash some keys to wake it up, enter my password, and it just hangs on the login attempt. There's no crash and no error, like I've seen in many other questions here - it just sits there. I can still hit "cancel" and go back to the Enter Password screen, and the "go back to sleep" function works fine. But attempting another login just results in another hang
This usually happens only after an extended period of sleeping - almost every time it goes overnight, but not when I step away for an hour or so.
It seems to have begun recently when I upgraded to Yosemite.