Metal roofing transfers rain noise more effectively than shingles. The drum effect is most pronounced when you're under an exposed metal roof, such as a porch or barn. In normal residential environments, there is ceiling insulation and an attic space, and the rain noise is barely noticed. In re-roofing situations where the old asphalt shingles are left in place with new metal installed over top, this leads to little or no noise transfer. Some folks deliberately open a window during a rainstorm in order to hear the relaxing rhythm of rain on their porch roof

If you're looking for the cheapest roof you can get, install shingles. If you enjoy roofing, install cheap shingles and you will soon get to replace them. A high-end asphalt shingle will be in a similar price range as the basic metal roof, and the metal roof is likely to outlast the "high-end" shingle roof.

Hail dents in a metal roof are rare. Dents visible from the ground would be even more unusual. If you wish to decrease the odds of an extremely unlikely event, install your metal on a steeply sloped roof and use a solid underlayment panel similar to what is used under asphalt shingles.

Paint eventually fades when exposed to sun. All paint and colors fade with time, but today's roof coatings are much higher quality than the ones being used even as little as ten or fifteen years ago. A 40-year warranty is pretty standard in today's industry. Be careful with "lifetime" warranties — many of these are merely talked on by the seller and are not a statement of quality by the paint manufacturer.