wow, that looks like a pretty decent waterblock. I do see some possible problems. First with the hosebarbs, the holes are soo small, I would ream them out a little, And with the block, Those posts are really far from the center, so far that the heat hardly sees them. I would move those in a ton, and shorten the total thickness of the block a little if you can. If thats a problem, I dont see why that block would be bad, its probably pretty decent.
Jon