I am from DC but have a lot of friends who live in the GTA. I will have to say that aside from seeing them this is one of the things I look most forward to in this great city.
Ultra is a nice blend of great food and a wonderful scene. In the summer there is a deck and in the winter a heated patio. Combined with a fine bar and staff this is a place you must go to while there.
In addition they throw some great private parties. I have been to several closed events there and have always had a good time. The space is a little tight, but it just makes it easier to meet all of the friendly Canadians!