I read this forum a lot before purchasing my P2C. It was the first tri bike had ever ridden. My impression from the forum was that fit was some exact science. People strongly recommend to get a fitting done. I was surprised when I did the initial fitting I was asked several times how does that feel? I thought they would measure me and then set the bike exactly a certain way.
I am not saying do not get a fit but learn everything you can during the session. Keep your measurements, bike and your body. I now log all the changes I make to the bike with also some scoring of what the change seemed to do in the way of power, aero and comfort. It is not perfect but more of a feeling. The one that is really tough is aero. I have been doing some tweaking lately but it has been so windy here that trying to see any aero consequences is impossible.
I am not saying do not get a fit but learn everything you can during the session. Keep your measurements, bike and your body. I now log all the changes I make to the bike with also some scoring of what the change seemed to do in the way of power, aero and comfort. It is not perfect but more of a feeling. The one that is really tough is aero. I have been doing some tweaking lately but it has been so windy here that trying to see any aero consequences is impossible.