Sure is a lotta parts for a unity gain buffer. Replace the BC549 with a darlington, like the MPSA13, and you can ditch the bootstrap bias circuit. Gotta wonder about why C2 is so large. I agree that an opamp buffer like the Centaur input offers a low parts count and best (most transparent) performance. A JFET would work well too, but that is a whole different can o' worms!