I grow my strawberries in gutters and it works beautifully. I change varieties every two years. The trick to growing in gutters is not drilling too many holes in the bottom of the gutter. For my gutters that are five ft. long (each) there are only three holes. No more than that; I only water once every two days. I use simple bagged potting soil then spray with fertilizer all summer long. I am only growing Mara des Bois this year a day-neutral, so I will have berries all season long. (these are established plants) remember the first year you grow strawberries remove all of the flowers. You will not have berries until year two.
And here is a picture of my ‘QUAD’ strawberry for Eric! The little white one was on a different stem. Tasted really good!