It has been a long time since I did thermodynamics but with basically no distance does the liquid make any difference?
I don't think it's about distance, but it might as well be. I think it's about specific heat capacity of water + its velocity in loop and energy [heat] exchange ratio. Imagine water in loop being a faster heatpipe with higher specific heat capacity than whatever liquid is in heatpipes + there's higher amount.
In theory, it should work, but Asus somehow botched it up. Maybe Acer will succeed, but I'm not sure about.
Overall, when You slap a random 240mm Asetek kit [cheap pump + cheap aluminum rad] AiO to any modern VGA, even with fullbody block, You'll get a superior cooling capacity for whole PCB [GPU, RAM, VRM/MOSFET, etc.]