I picked up an omnibus edition of "Forever War", "Forever Free" and "Forever Peace" a few days ago. I had read the first two a while back, and they remain among my favorites, so much so that I can't leave them lying around or I'll reread whole sections every time I walk past them.
I had high hopes for "Forever Peace", which is not a bad book by any means, but is perhaps a bit more ordinary than the excellent "Forever War" or the engaging "Forever Free". Both "Forever Peace" and "Forever Free" were written in the late nineties, around 25 years after "Forever War". "Forever Free" is less of a departure, as it expands on the technologies and situations of "Forever War", with a bit more philosophy and a bit less technology. "Forever Peace" seems less connected, there is in fact almost nothing to suggest that the story takes place in the same world as the other two novels.
It starts reasonably enough, with the life of Julian Class, a part-time soldierboy operator who joins with his platoon to form a kind of collective consciousness for ten days out of each month. During the other twenty-odd days, Class is a researcher and lecturer in physics. Both aspects of his life are introduced and fleshed out well. The work begins to falter when it the main dynamic of the second half of the work is unveiled. We are meant to believe that the immediate choice facing humanity is either utter and immediate self-destruction or utter and more or less immediate pacification. It's the forced juxtaposition that hurts the work.
This is not to say that parts of the work aren't genuinely enjoyable. Haldeman teases aspects out of "jacking" that other authors dealing with similar material haven't picked up. Most notable is his idea the that the prolonged joining of minds through technology leads to greater sympathy of joined individuals for the whole of humankind.
At any rate, it's a fairly short read and enjoyable enough if you're willing to invest the time.