Both of the motorhomes in my signature have metal roofs. Had rubber roofs in previous motorhomes and much prefer having metal roofs for ease of maintenance.
The 1st thing I did when I purchased each one was to apply 4" wide Eternabond tape around the entire perimeter of the roof seams where the roof meets the sides and seams on the front and rear caps. I also apply Eternabond tape around all roof vents, skylights, antennae mounts, ladder, etc. Been using Eternabond on 8 different motorhomes for 20 years and never had a leak after applying this tape.