reputation measurements like these can be useful within a certain context, Ive also seen these systems reduced to mutual admiration societies as well
Ive seen them done in several ways, when I was a BB admin we didnt have a defined automated system, but often employed custom titles for certain members that held specific expertise.
They do provide a clue to helpfulness if not necessarily expertise. IMO I like them, provided they don't burden Vbull. (Which is why we didn't employ it but there where +50K members)