I currently have a 2016 FX 7.1 and am really thinking about getting the FX 7.3 which does have a carbon fork, slightly narrower tires and a 9 speed cassette. I chatted with a rep. from Trek and she told me that if I wanted to upgrade, I would feel more of a difference with the FX 7.3 over the 7.2. I'm not sure on the color yet and am deciding between red or white. I like white but am a little concerned that it might show scratches a little more. I believe with the 7.3, you get the lighter aluminum frame and carbon fork and is about 2 lbs. lighter I think.