http://www.bwdesign.orcon.net.nz/wb2/Assem1.avi
Uses Xvid codec - I recommend VLC player (for everything actually, not just this avi)
Not what i envisaged (actually, i think this would perform worse, and has been suggested before) but it may get an idea rolling for you. Obviously not the full jets are shown, nor is that the full block base size; actually, the only reason im putting this up is because i said i would, i believe its next to useless.
WRT your jet testing, will less jets focused in the right places make for better cooling due to the velocity? The images you've show still show what appears to be quite a number of jets (more than the cascade, even?)
Would having less result in more water velocity, or have you increased the velocity to as high as you're able to (from what you've said, it seems so)
After looking at a die size, and the area of heat that it creates, the size of a key on a keyboard (14x14ish) should create enough cooling to let the rest be cooled by the outflow, would it not?
/random musings