They're all "machines" and all machines need maintenance and eventually some form of rebuilding to keep going. NID's seem to be about in the middle of the road on that from a design standpoint (I only have one). Yeah, a Pgun or Kgun will hold up to bazillions of rounds, but try carrying one of the target models that can make that claim on a 5 or 10 mile day hunt! Even Pguns wear out and need rebuilding. I don't know of any game guns that can go forever without some maintenance and often rebuilding. Is that a reason to discredit the design? I think, Mr. Bomb, you are in the minority on this one.