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Please bring back the days of buying a program on a disc.
Then what would you do when you obtain your next computer and it doesn't have a disk drive in it. Or, you scratch your disk and it unreadable. I too prefer that some changes not happen, but then, I recognize that I can't change the world and i have to adapt. In my opinion your lack of internet is a bigger issue than where or what to house your app on.
Also remember that on that Mac the issue (as mentioned above I think) is more graphics card related than CPU related. What graphics exactly is in that Mac you are considering?