Expensive meal - you're paying for the ambiance, not the food.
Overall my experience at Trevi was disappointing. At worst, i was expecting food on par with my local pizza place, and at best a delight to my senses.
The mojito i ordered was fine.
My entree (chicken piccata) was bland. The pasta was tasteless, the sauce wasnt sweet or tangy, the chicken had none of the piccata "kick" (from lemon).
The coffee tasted like hot black water.
The gelati i had was amazing.
In short, skip the meal and go for dessert