I started reading Quicksilver, and found the Waterhouse plot fascinating. I couldn't put the book down throughout this section, but then it just switched to a completely separate character, and my interest in the book nosedived. Perhaps because of my science background and my general interest in the history of science, the Shaftoe stuff just couldn't hold my attention in comparison.
It's well-written and meticulous, and I do plan on one day returning to the book, but I was so disappointed by the character shift that it may not be for a long time.