In Canada we have to use a gascolator. On all my airplanes I have mounted it in the stick bay, just aft of the #2 bulkhead and below the fuel selector. My airplanes are not left outside and in 1500 hours I have only rarely seen drops of water, from the tanks or the gascolator.
I believe that gascolators have been given a bad rap due to how crude and "garden tractor like" they used to be. The Andair unit, and the blue model offered by ACS and Van's are quality units. I sump not only for water but to see if there are any other contaminates in the fuel system. How do you sump an inline filter? How do you know if there is material building up in the inline filter? A gascolator lets you "look" at the cleanliness of your fuel supply before every flight. Have I found much in 14 years of RV/rocket flight? No, but that is more a function of how clean aviation fuel is at the locations where I have stopped for fuel. Years ago when flying a Citabria, which was burning auto fuel, I one time sumped the tanks and gascolator and was amazed at how much water I found. A year of flying, nothing every time, and then samples that had more rusty water then fuel! The auto fuel was purchased at the same location every time.
The inline filters that have come with some of my fuel systems are not sitting on the shelf, they have been sold!