I have been to Sienna several times for lunch, but I decided to take an out of town friend there for dinner last week. I ordered the salmon entree, and it was excellent. The salmon was done a little more than I would have considered medium-rare, but it was very good, and the arugula and tomato/eggplant dish were unbelievably flavorful, so I did not mind at all.
I enjoyed my meal so much that I went the next day with a client even though we did not have a reservation. I ordered a 'side arugula salad' with a side of a mozzarella-stuffed meatball. I also ordered the tomato/eggplant that accompanied the salmon the day before because it was that good. The meal was great, and we were very glad to be seated even though the restaurant was packed.
The service was pretty good each time. I do not think I have ever been dissatisfied with the service. BTW, the Malbec Nieto wine from Mendoza, Argentina was excellent as well. It went really well with the tomato-based dishes that we ordered.