Your suggestion, being XP based, is basically a reflection of the reputation approach. Reputation searching would miss gems but it would be extremely helpful overall. Setting a threshold might be nice. Only nodes 10+. That would miss few, if any, of the gems while weeding out lots of noise.
If I ask an Excel question, I probably want an answer from jmcnamara. If I ask an inline C question, I probably want an answer from syphilis. If I ask a Moose question, I probably want an answer from stvn. If I ask an Ajax question, I am vain enough to suggest I probably want an answer from myself. None of these monks is in the top 25 or even 50.