If you buy any model you would have 14 days to decide if it is enough. Right now if you buy a Mac you have until Jan 22nd to return. There is NO swapping anything in these machines. Whatever you get is it. You can't even change or replace the SSD. That is why I have been saying spec it up as much as you can but also within reason. There is a point of diminishing returns the higher specification you go. As others have said in 3-4 years there will be a much better Mac so getting better components only does so much. That being said I don't think it will be like Intel where your machine slows down and basic tasks just suck. These M1 chips will be slow compared to new CPU/architecture and process but the M1 is probably not going to age the same as Intel models. It will be interesting to see. I have a feeling these are going to last longer as long as nothing fails.