I had an F55 (an Al bike, not carbon like the F4) for 2 years and had a weld break at the chainstay/BB junction. Felt has agreed to replace it on warranty. So, I am not sure about Felt's overall quality. Likely it is no better or worse than most bike manufacturers that get frames from Taiwan - which is almost all of them. But, I can say that they stand behind their warranty.

I think the bike is a really good value.