Since you like the 7.5FX very much, I think there are a couple of key questions to be considered.
You mention durability and performance as potential improvements with the upgrade. How are these lacking in your experience with the 7.5FX? Are you aware that these two elements are sometimes contradictory in cycling?
I ask these questions knowing nothing about the bikes, but for hybrids, I agree that in general a hybrid is not purchased for performance at all, so paying for carbon may not be a wise investment. Although if the ride is more comfortable, or it fills a need for you, it may well be worth it to you.
Also, in cycling, higher cost bikes are not necessarily more durable, but lighter and potentially less durable. A premium is paid for lightness on the highest end bikes, and it is sometimes acheived at the loss of durability. Remember at the highest end, durability isn't the selling point, the weight is... a vendor may choose to give up durability or strength if they can cut 10 grams from a component...
Not that they would intentionally make a component inferior, but can hollow chain pins really be as strong as solid pins? But, if it is strong enough for the user, it is fine. Can the titanium pedals with published weight limits really be as strong as the chromoly equivalents at half the price and 1.25 times the weight and no published weight limits? But, for a light rider who wants a lighter pedal, it will do the job well.
Just food for thought...
So, what do you want to gain?
It could well be that the $2000+ hybrid might be the right choice for you. If it is, and you can afford it, enjoy it. But, I need more info before I could in good conscience advise you either way.