How can you be living in the U.P. and say that about steel roofs? Every roof I see is steel. Shed all that lake effect!!
I've got three metal roofs, one on my shop, one on my garage, and one on a house, as well as two houses with composite shingles and three composite garages.
The metal roofs on the garage and shop work well, except for the constant shedding of snow in front of the garage door. None of the contractors I've spoken with recommend snow guards. In order to be effective with our climate, they say that you need a snow guard at almost every roof purlin , which becomes costly real fast..
Other than the snow shedding (and compacting) in front of the garage doors, I like the metal roofs on the garage and shop.
The metal roof on the lake house is another animal completely, as the house has a valley over a 16'x16' addition, and a 10/12 pitch roof.
Snow sheds fine off the back of the house, but gets caught on both valleys, especially the north side. Remember, 200-300+ inches of snowfall is common here.
The sunshine and warmer weather in April eventually melts the accumulated snow, but first it turns to ice, which rips the steel ridges like a can opener as it gradually slides down the roof, like a glacier, towards the eaves.
This is common on roofs with valleys here, and all of the contractors I've spoken to locally recommend a conventional roof if the roof has valleys.
One went so far as to take pictures of ripped roofs to show to customers who insisted on metal but have inappropriate roof lines.