TD i got what i assume to you will be a stupid question, but to me its a common sense conflict with the way the manufacturers are building the towers these days.
OK first lets start with what i believe the common sense side of this would show, heat is the worst enemy of any performance machine including computers, and as everyone knows heat rises.
now to the confusion, the manufacturers of these high performance towers seem to be trending towards placing PSU's at the bottom of the tower. my PSU, although not super hot, generates some heat and gets progressively warmer over time when higher amounts of current is being used to run the system, IE to play games.
the question, if it is not already apparent is simple, why fight physics and place the PSU on the bottom of the case when it could be placed at the top and aid in reducing internal tower heat?
great build by the way!!!!