Metal roofs are gaining popularity due to their longevity and beneficial effects on property values. However, you can't just slap a metal board down on your house; you have to have certain features to make the roof perform optimally. Without these features, you can be left with noise and large utility bills, but with the features, you can be a lot more comfortable.
A lot of the myths surrounding metal roofing have to do with temperature control, either that the metal will heat up too much in summer or increase the amount of cold you feel in winter. The metal really does not have anything to do with that. It's the insulation under the roof, in the attic or crawlspace, that affects how much cold air or hot air gets in or out of the house. If you have poor insulation, it's going to feel like you can't keep a consistent temperature in the house without running the heater or air conditioning all the time. If you have great insulation, though, then your house will feel comfortable. Have the insulation in your home checked out before you blame any temperature fluctuations on the metal roof.
When things hit metal in general, they make quite a racket. Metal roofs, though, are an exception. Even smaller hail isn't that loud when it hits a metal roof if the metal roof has solid sheathing underneath it. If you don't have that sheathing, then you can hear every sound from every item that hits the metal. But if you have sheathing installed properly, that's going to cut down on a lot of outside noise.
Metal roofs come in several styles, and one style in particular can be very helpful if your area is prone to hailstorms. Textured and molded tiles, made to look like asphalt and wood tiles, can hide minor damage from small hail. Of course, if you get hail the size of baseballs or graprefruit, then the style of metal roof won't matter that much; hail that size will leave evidence of damage on most any roofing material. But if you have mostly small or medium hail, those textured tiles will cover up little dents better than a smooth metal roof.
Talk to metal roof manufacturers about what they've noticed regarding the performance of metal roofs in your city. This way, you can get a better idea of what to expect if you decide to get a metal roof.