Awesome, I'll give it another go at some point, then; thanks! I haven't read A Murder of Quality, but I did add it to my list after your first post, since I like mysteries, too.
The only other Smiley-connected novel I've gotten through is The Spy Who Came in From the Cold, which I liked more than you did. It's a let-down from a Smiley perspective, true, but as a standalone spy story, I thought it was pretty solid.