I've wanted to read these since Lord John Grey first appears in Voyager, which is book three of Gabaldon's Outlander series. It took a while to get into. My attention was too divided at first to really get into the book, but the action picked up and I couldn't put it down! I was a little leery of the whole spies and treason focus of the plot, but it works out well. A little confusing but not so much that I really got lost.
I'm hoping to start book two, Lord John and the Brotherhood of the Blade, within a the next couple of days.