I have a Trek 7.5FX and DH has a 7300. They are very different bikes. The FX series is much lighter, yet durable. The stock FX is not as upright as the 7000 series. That can be remedied with a stem riser. I did this to my FX and I like it so much better (I need to be upright or have drop bars for my comfort). Is it a worthwhile upgrade? That is up to you. It's all about what makes you happy and want to ride even more. You need to head out to several LBS' and try out what they have in your budget. Don't limit yourself to just Trek, all the major manufacturers have similar models (Specialized Vita and Giant Dash, for example). Exploring the shops and test riding the different models should be a fun experience that ends with a bike that puts a smile on your face.
Enjoy the hunt,
P2
2018 Trek Silque SLR6 - Selle SMP Glider
2018 Specialized Dolce EVO Comp - Selle SMP Glider
2011 Trek Madone 5.2 WSD -Selle SMP Glider
2013 Giant TCX W - Oura 143