La casina is quite nice. It has all you might need. It is just 15 min walk from the Cathedral and the Royal Palace. The only thing to note would be the smell from the backyard and the exhaust fumes from the street but if you don't open the windows and use the AC, that will not be a big problem. After all, it is almost downtown and one can't expect clean air there.
Mario is a great host. He even helped us with the washing as the washer was out of order.
I can recommend la casina as it was quite good value for money.