I use tor most often for irc, although I have recently shifted my customary irc hangout to the ORC away from a little one i used to hang out at, and on ORC tor proxying is a prerequesite.
As a user of tor with irc, it has become the most common bitch of anyone i've talked to about the endless process of dying circuits, and while thinking about it recently i realised there was one thing that could be built into tor that would reduce the number of mis-guesses of long-lived tor nodes: accounting!
If a node has bandwidth accounting, it should not be listed as long lived, because obviously it is likely to go down at any moment. I don't know if it will make that much difference to persistent session use on tor or not, but I think that it is only logical that bandwidth accounting should flag a 'not long lived' flag on the server information so that circuits to irc and ssh and other long lived connections don't use it. i know this might 'reduce anonymity' through the weakening of defenses against traffic analysis, but endless reconnections to irc servers, in my experience, is annoying both to myself and to the endless timeouts in the ORC which is exclusively tor-accessible.
Regards,
David Vennik