Yeah I don't really get what the problem is either. I'm not sure is the size/layout of each folder is saved, but you do have the option to open all new folders in new windows.
The problem I see with a spatial finder, is that of the problem with other spatial filing system - i.e. filing systems that you find in the office, work etc. - People forget where something is, file something away that they need more often than they think, wish the system wasn't organized like it is, or can never find something that someone else has filed.
I like flexibility, and the spacial way of doing things bugs me a bit. What if I decide 1000 images should not be filed under Holidays>2005 but Holidays>2005>Holland. Now that huge "space" i had for "2005" needs to be big enough to hold a few nested folders.
In a spatial system I would need to resize, reorder etc. each window, but in a column view everything is automatically neat and simple.
I also foresee myself having many more Finder windows open for a spatial system (I know I did when I used OS 9).
For example: I want a folder nested 8 levels deep. That is 8 double-clicks and 8 separate windows open in a spatial system. In a column (or list) view it's 8 clicks, one window AND (assuming in the spatial system some of the windows were large) I can easily see the hierarchy of that folder. The benefits of spatial seem thin to me, but I'm not about to tell anyone that they are using their computer wrong if that's what they prefer!
Also, quite what this has to do with the control key I cant remember...