I certainly like this better than gluing individual heat sinks to individual chips and hoping they don't fall off and hit the motherboard. Still, I'm not sure it's that much of an improvement if you do use a standard high end card and have a cystin water cooling loop.
Now, replace the standard waterblock with one connected to a sealed loop and I think that might be a good alternative. Replacing the waterblock, pump, and the radiator is even worse than replacing just the block.
Closed loop coolers have even less availability than waterblocks for video cards and they invariably have those heatsinks on the individual chips I mentioned.