I see! thanks CD!
As for the design, well, parallel designs that split the waterflow work just fine, it's just a little more plumbing. It works well because it sometimes allows for better flow (i.e. a bigger pump).
In this case, Morphling1 eliminated the extra plumbing by linking the outlets through the plexi.
I would expect that the flow would be very nice within the block, but would be most restricted because it has to bend 90 degrees twice, for each outlet, then go through a channel in plexi that may be smaller than the corresponding channel in the Cu block.
But then again, the channels are so wide within the block, that it should compensate nicely for anything. Most of the heat will be in the center, and those long posts will help a lot.
One advantage of spiral designs is that the channels leave a big fat corner to collect extra heat.
Hold up... do I see that the block intake in the plexi is formed in a cone ("V") shape? Morphling1, you shouldn't restrict the flow like that, it's really not necessary! I know you're trying to shoot the water as far down as possible, but it shouldn't be a problem at all, really!
I like the big kick-as* barbs...