@MikeB gave good answer, better to confirm but I am pretty positive that with Check Point, you can NOT import config from one appliance onto another, unless its same appliance model and same version. I am pretty sure logical reasoning for that is say if you have 4400 appliance and you want to import backup into, I dont know, lets say for argument's sake, 16000 box. Well, that would never work, as interface layout and config is totally different. Now, if 2 appliances you are talking about have exact same hardware features, then it might be doable, but most likely not supported.
I recall at some point Fortinet support had process to do this on 2 different models, but then they deleted it, as people were doing it, s*** would happen and they would then call support and complain. All in all, always better to follow vendor's recommendations...sort of goes without saying : )