The patches are in limbo for days, weeks, months or even years before being evaluated

I understand the complexity of the task, but I would like to say that in my opinion the issues with attached patches should take the priority over all other things. Beside the fact that it could be quite frustrating to be ignored for so much time, this may cause several troubles, for example you cannot touch a piece of code without risking to invalidate an existing patch, or some reporters could even provide a similar patch for the same issue.
I hope that you won't misunderstand my words, but I think that this is quite vital for an open source project.