Cold Mountain was a fine read, and Frazier's successor to that one - Thirteen Moons - is wonderful, one of my favorite books. Nightwoods was perfectly good and worth the time each of the few times i've read it. Varina i remember almost nothing about but i don't remember it being bad.
The Trackers was not good. The writing was rudimentary and the only character worth reading about was the old cowboy Faro who was, sadly, undeveloped beyond a stereotype. The rest of the characters being tedious idiots. The plot might have been compelling were the writing better and the characters worth it. Maybe.
Hopefully the next novel is more like the first two.