What positive things the book says about cryonics? It asserts that personal identity is contained in the connectome but, from what's been said here, it seems to follow the standard anti-cryonics tropes on other counts. While that would be useful to reference in heated intellectual debates with cryonics opponents (just refute the standard anti-cryonics tropes as per the usual procedure), I'm not sure it would help cryonics' standing among the general public.
Sebastian Seung's new book Connectome: How the Brain's Wiring Makes Us Who We Are is very well-written, and aimed at a broad audience.
The penultimate chapter explains why cryonics might make sense given our current understanding of the brain.
The final chapter does the same for mind uploading.
Transhumanism continues its march into the mainstream.
Despite its flaws, I recommend the book.