Cryoburn
I finished reading Cryoburn, the latest Miles Vorkosigan novel, not that long ago. It was... fine. But in the end, the thought that came to my mind after reading it was this:
I did begin a story placed about 100 years after the Downfall, but it proved both sinister and depressing. ... I found that even so early there was an outcrop of revolutionary plots, about a center of secret Satanistic religion; while Gondorian boys were playing at being Orcs and going round doing damage. I could have written a 'thriller' about the plot and its discovery and overthrow - but it would be just that. Not worth doing.
That's J.R.R. Tolkien (in Letter #256) discussing his abandoned story The New Shadow. From the little of it that he actually wrote, I'm inclined to agree with his assessment: I expect that I would have read and more or less enjoyed the book if he'd finished it, but I doubt that it would have held a candle to The Lord of the Rings or even The Hobbit.
And that's more or less where I am with Cryoburn. It's a perfectly good mystery novel, and I can't complain too much about further development of a world and characters that I care about. But while "not worth doing" is probably too harsh, I still don't think it said anything strikingly new about any of them. (I half suspect that it was shooting to make some sort of broad statement about fathers and sons, but if so it didn't really click with me.)