Supporting your point, astrophysicists have been using citation counts in this way for quite a few years thanks to the citation data provided by the NASA Astrop

Supporting your point, astrophysicists have been using citation counts in this way for quite a few years thanks to the citation data provided by the NASA Astrophysical Data System. Citation counts are biased, but at present they are the best we have. Their main attraction is that they are transparent and hence trustworthy, and a proxy for what we really care about: aggregate expert judgement of importance. Any replacement will have improve one or both dimensions--I don't think timeliness alone is enough.