Everyone has law suits from time to time but IKO has a track record for it. The product flat out scares me because I am trying to build a reputation on quality, and IKO wouldn't fit well into the brand I am tryign to build.
Difference between the IKO suits and the other manufacturers is just who is sueing them. I do not think that CertainTeed or the others were sued by not one but three States (Yes States, New Jersey, Conneticut and one other) sued IKO. Class actions are a result of greedy lawyers, not necessarily the truth when a state's attorney general is sueing you for not honoring your warranty.
Google it.