For drinking? Yes, the water stops tasting like chlorine and iron. It also filters lead, fluoride and other unvanted elements. Simple carbon filter I believe.
Not sure it makes any difference for the back yard though.
Oh yes, North American cities in the east coast are known to have many dwelling built with lead pipes. Montréal is particularly bad, due to the high amount of multidwelling midrise plexes.
The city is running its replacement program, but it's painfully slow. The first thing I did when moving in here was to install the filter.
There's nothing really to complain about. Just have to be patient and keep the children from drinking unfiltered tap water.