In NYC across from Central Park is the iconic building, The St. Urban, which originally had a beautiful slate roof but due to the cost of repairing and continued maintenance was removed and replaced with a beautiful overlapping copper shingled roof.
The great roof and tower of the 1906 Saint Urban apartment house building was originally a slate roof but had been replaced in the 1960's with a 6,000 square feet asphalt roof. The asphalt shingles were not as durable as slate. Due to deterioration the asphalt and copper detailing was damaged by succeeding generations of riggers, so the asphalt and the balcony running along the 10th-floor level was damaged over time and was taken down instead of repaired. The balcony had shielded the lower facade from water and its removal created widespread leaks. Windows later cut into the mansard roof and produced more leaks. Its $750,000 project roof-work program rebuilt the copper dormers and the turret, putting in new gutters and replacing the asphalt, not with slate, but with overlapping copper shingles, so now it is just as durable as, and weighs much less than, the building's original slate roof.
I am not sure of the cost factor for copper shingles, but if your home is as you stated, "worth-it" then perhaps this is a better alternative.
where I have the picture I took and the history of the St. Urban, providing the above info.