A few days ago I finished Hellburner by C.J. Cherryh.

Hellburner is a sequel to Heavy Time, which I wrote about here.  Heavy Time was not an easy read, since a good part of the book involves a man who has been so badly traumatized that he can't function normally.  Hellburner is actually a harder read - it spends even more time in the same traumatized man's head, after another accident has caused him to flip out again.

On top of that, it is often difficult to follow the action in the book.  Too much exposition can be a problem for a novel, but too little exposition is also a problem.  Following the action in this book felt nearly impossible.

I don't know if I would have picked it up if I knew it was a direct sequel to Heavy Time, and I don't think I will pick up any other books that are directly connected.