The Cadogan "Tuscany" guide curiously rates this hotel as very expensive. It isn't, tho we did get a special offer. Indeed it's quite cheap, we thought. The view from the window of our room (44) was luminous with the sun shining on the jumble of houses going up a hill and the dome and tower of the duomo rising above it. The room was good sized tho very plain. We once stayed in a perfectly ordinary hotel in Trento which became memorable for me, and where I intend to revisit, because they had reproduced on one wall a secular fresco from the Bishop's palace. It's a simple way to make a room memorable and certainly Siena with its wonderful frescos would lend itself to the same treatment.
As is common with less expensive hotels, it lacks much common space. The breakfast room is not accessible for the very disabled (Siena would not be a good place, anyway, for those with disabilities.) Staff were friendly and efficient, breakfast copious tho rather boring, good internet.