Excellent all around. Coffee's great, jelly that comes with the croissants is outstanding (as are the croissants).
They give you a lot of food, so be aware of that, but otherwise, great morning experience in Vegas at the Venetian.
Definitely go to the restaurant on the 10th floor, though. The one on the main floor of the casino is more of a deli/quick stop and the lines are tremendously long. The restaurant is much more calm and organized