My first exposure to Maury's was at the recommendation of a friend who is not only a professional musician, but in a past life did work on high-end acoustic instruments. My initial purchase was a bone saddle and bone bridge pins for my Martin HD35. I have since become a repeat purchaser, having just purchased a K&K pickup and preamp for the same instrument.
There's really no weakness here... the prices are great, the response was quick, and the customer service was exemplary. I'm now a huge Maury's ambassador.
I will post my opinion of the K&K system in the near future when I get it installed and get some gig experience with it, but if Maury is high on it, then I am sure that it will be great.