I don't think the pickup is the significant difference in the Nate Mendel, I think it is that the neck is thinner and narrower than the standard precision, and that is the only shipping P model that that is the case of. Anyone can change the pickup in an instrument, sourcing and changing the neck is a lot harder.
I think it is not a question of ignoring the model because it is an artist model is a different thing to actually going out of your way to buy it because of the artist affiliation, rather than whatever difference that creates, such as I notice there is a (increadably expensive) George Harrison telecaster. Some people will presumably buy it because of the George Harrison link (although for the life of me I don't remember a picture of him playing a telecaster, although he obviously must have), and some people will buy it because it is the only model made with a rosewood body. I doubt that anyone would deliberately not buy it just because it was connected to George Harrison somehow.
Although I suspect most people would avoid it because it is almost £3k for a telecaster, which frankly everyone who has ever held a saw should be able to make in their lunchtimes!