well I can understand the I/O ports would be different...but I was just looking over a dv7 body and I can't really tell the differences other than the i/o and the stated internal up-teched components. hp or any other corp for that matter are not in the business of redesigning chassis any more than Ford or Chrysler was in their various lines of cars that had a basic body and different internal components. They just branded them a different name. If I ever had the pleasure of hearing to dim-wits argue that a mercury was better of worse than a ford I would be laughing my head off. Somethings got to fit?
You'd think that would be true, but having dismantled many notebooks, I can tell you it's not true. The chassis and board designs change from model to model in most (if not all) cases.