Well, I suppose if it's done right then that'll be ok... but honestly, I think the 'apocalyptic war between man and machine' thing could render it all very dull and unfeeling. The earlier Terminator movies were all set in 'our' world, with settings and events and character motivations we can understand and relate to. More reality, less science fiction. Any movie set during the war is going to go in the other direction: characters whose backgrounds and environments are beyond anything we can understand.
I'm thinking of the Matrix movies: when they take place within the familiar environment of the Matrix, it all feels more human and more like something we can connect to. When it's just some guys in futuristic war machines fighting against evil robots in a post-apocalyptic wasteland, it loses that familiarity and becomes a whole lot more generic.