Although my favourite Terroni in the city is the newest one up by Summerhill and Rosedale station (highly recommend going for their rooftop patio, it's one of the best hidden gems in the neighbourhood), the Queen West location has it's own perks and charms.
Service
Pretty smooth from start to end. I received a phone call to confirm my reservations and they even asked if I wanted indoor or outdoor seating. Granted I went on a Monday night but it was still fairly buzzing in the dining rooms so it is nice to see places that do still do resos for the patio. Our waitress checked in regularly but wasn't disruptive or pushy. She also split all our checks properly on the first go (I know that sounds like something everyone should be able to do but there always seems to be some kind of mistake).
Food
I've eaten at both the other Terroni locations so I can say the food is consistent here to the others. I had a charcuterie board which had a nice mix of cheeses and cured meats. My only complaint is I wish the board came with honey or preserve of some kind to pair with the cheese. The cheese board does so I imagined the meat and cheese would? My friends had a pizza and beet salad which also looked great.
Drinks
Although I got the bellini this time (which is perfect for a warm day out on the patio), I recommend the Terroni sour with amaretto. It's very easy to drink and has that perfect sweet and sour flavour.
Overall Ambiance
This is a great place to go for a nice, casual drinks with friends, date or night out with the family. The backyard style patio is adorable and quiet/secluded from the city bustle. Only thing to keep in mind is Terroni is their "our way or the highway" attitude when it comes to their menus. If you are picky and want to make a starbucks-like series of modifications I would not recommend.
It isn't by any means the best Italian in Toronto, but Terroni gets top points for good selection of food, drinks and general service. I would recommend the midtown location first, than this one and last Adelaide (wasn't a huge fan of that one's layout).