I think it depends on what changes you were hoping for. For some, the drop in carbs (and probably sodium) when they ditch the processed foods results in a quick drop of a few pounds and that's such a good feeling. Other things like acne, joint pain, etc. might take longer. Other more serious issues may be very much improved, but never totally healed. Still, for serious issues, very much improved is a very good thing.
I think it also depends on how you were eating before. I never experienced carb flu, but I had no idea that McD, and microwave meals had become a mainstay of many people's diets. If before Primal most of your meals were homecooked and the biggest change was the quality of food (factory animals to pastured, etc.) then the long term benefits (I believe) will be more evident than the short term gains.
Anyway, welcome to the tribe.
"Right is right, even if no one is doing it; wrong is wrong, even if everyone is doing it." - St. Augustine