With my (limited) experience, I would say the A340-600 is the worst aircraft type when it comes to water accumulation in fuel tanks; we call it the fuel-to-water-converter:
You take out gallons of water every other day, and the recent incidents concerning the ruptured engine feed pipes are very likely linked to frozen (!) thermal relief valves (no, they are not located in the sump areas!!!).
It appears that Mr. B´s design to feed water from the sumps into the boost pump areas is superior to Mr. A´s water "mixing" philosophy.
Long live the A340-500/600, the job-saving aeroplane! ;-)
J.V.