Nice explaination.
I think before burnin didnt test the advantages of watercooling its all speculation. Only when there is a reasonable advantage it would make sense to go that route. So i hope he will test it.
And i wait for an answer from hetzner if they would allow watercooling in their datacentres anyway.
been there, done that. in 2011 they did not allow it ... i think that especially in germany its not very clever to host miners in datacenters due the high costs for electricity.