Well, so far so good. The valve has been fine, so I installed the filter today. Very nice, easy installation. Here is a comparison photo of the new and old valves:
I pick up about another 20cm of water in the tank, which is almost 15%, or ~210 liters, and I like having the filter in the tank before the pump.
This thing lasts a month, I'll change out the one in the other tank.