So I am in the process of getting bids for a new roof. I am looking at getting either the certainteed landmark or presidential shake. I have done my homework as far as products go, however my question lies with who to hire. I have received approx. 4 bids. 3 of them were fairly competitive and in the same ballpark and one was 4k lower. Workmanship warranties included 5,7, and 10 years. What should I be looking at to help me make the best decision possible? Thanks- Andrew