This discussion is really just a big old waste of time and is all speculation. There is absolutely no way from the consumer point of view that we can objectively determine what the "maxed out strength" is of each system.
The only way to do so would be to have a benchmarking program much like 3d mark 06 which is used for the PC industry. If this could be run on both consoles, it would give us an OBJECTIVE number-based rating of their overall graphical/computational power. Unfortunately a program like this just is not available.
So again, this is all speculation and just a good ol' waste of time.