I was there two weeks ago and have been going there since it opened (and before, when it was l'Impero) and it is always satisfying. As everyone says, the pastas are exceptional, I love the quail appetizer, and my favorite main course is the lamb chops, though the daily specials are usually worth ordering, sometimes it's a pasta and sometimes a main course. I always have the affogato for dessert. It's simple and delicious and light enough after a heavy meal. Also, don't hesitate to order wines from the low end of the list. I've had many for $35 to $45 that have been excellent. They really know how to find the gems.
I went to Convivio several times over the summer, for lunch and dinner, and was very impressed every time. I think I echo Sam Sifton's thoughts in tomorrow's NYT review of White's new restaurant, that there is a risk the Chef is getting spread too thin, but from what I saw over the summer Convivio remains in very capable hands. You can rarely go wrong with the pastas, and most of the fish entrées were quite good. The only misfire I had was a very, very dry cornish hen at one lunch.
45 Tudor City Place, New York, NY 10017