Tim went into a lot of detail - which I agree with. Lots of things affect ride. Chain stays length etc. These days as most things are composite molds, it is not often an option to change anything and IMO the carbon stock stuff is better all things considered than a custom frame.
I learned this by crashing (several times) and bending forks in the steel days. I was also a pseudo frame builder. I could feel about 10mm. In my head I could feel 5. Tire pressure will give you a 2-3 mm effect (and with shocks way more).