Had Allez Epic Carbon Fiber (lugged), and three years later adhesive let go in one of the chain stays.
Specialized replaced it, no questions asked, and between them and the LBS, covered the costs of changing the components from one frame to the next.

I pay attn to the frame warranty. I will be buying a new bike next week, after some time researching. Had decided on a Pinarello FP5, went to get it in the next town over, and as the salesman is talking he tells me it has a two yr warranty. He lost the sale right there. He tried to cover it over by saying that Pinnarello has very few warranty claims. I told him I would think so, since they have probably the shortest road bike warranty in the business.

I don't find it necessary to have a limited lifetime warranty, but want at least 5 years. What Pinnarello is doing tells me there must be problems if they can't stand behind their bikes any longer than that.