If you haven't seen it yet, it is worth reading. On Antiquitopia, Jared Calaway has a very detailed review of Peter Schaefer's newest, Jesus in the Talmud. I haven't read the book myself yet, but it has been on my list (along with a huge stack sitting here in my office - gosh there have been some good books released lately!). Thanks Jared for an insightful review.
As for who the counternarrative might be directed to, maybe it isn't. Perhaps the narrative is not counternarrative or polemic with an opponent, but simply represents a formulation of the Jesus traditions within rabbinism for rabbinism?