We mainly use GAF and they have a large presence in my area. On occasion, we've installed Certainteed and OC and don't have any complaints about them. The couple times we used Tamco, I was not impressed and it took a while for them to seal and that's in the Florida sun. What are you guys installing? Tell me your likes and dislikes. Additionally, do your shingle wrappers have the Miami-Dade product approval logo on them?
http://www.affordableroofingcontractors.com
http://www.affordableroofingcontractors.com