Just a thought. If you enjoyed these books, you might like _Old Man's War_.
I didn't really care for Old Man's War . It's a fun read, but it's popcorn. It was a bit too juvenile nanotech wankfest for me. Nominally it looks at subjects like long life, implanted AIs, etc., but it doesn't really do anything with them other than go "squeeeee look at the tooyyyyyys". EDIT: If you want to just bask in the sheer glory of superior firepower and gallows humor, and maybe even occasionally see somethin…
I'd also recommend his Redliners, which deals in large part with the need to re-establish empathy between soldiers and the civilians they fight for. Some elements of the plot get a bit silly, but Drake was exorcising some serious personal ghosts in that one, and his conviction really shines through.