Wood shakes and shingles are beautiful but not the most durable. Even though they are made of hard woods like cedar they cannot match the lifespan of other products like Spanish tile or even normal asphalt tiles.
They are very eco friendly because they biodegrade completely and some historic preservation societies/neighborhoods may require them to match the time period or character of a neighborhood.
In most circumstances we advise against installing new wood shake roofs here in Virginia because of our high termite population, wet springs and autumns and simply because we feel that there are much better options. If you still have your heart set on shakes or shingles or if you are required to use them because of your subdivision requirements, then we of course will be happy to help you!