Montali is amazing. My wife and I (both vegan) stayed there for two nights recently, and we loved it.
We ate all our meals there, including lunch, and we spent most of each meal exclaiming at how good the food was. At dinner, they really pull out all the stops, delivering delicious gourmet four course meals. Imagine if Horizons or Dragonfly opened a hotel, and that's Montali.
My one complaint about the food is the tea. I asked for black tea and was given Twinings English Breakfast in a bag. Considering the incredibly high quality of the food and other drinks, this really stuck out as a weakness. I'd love to see Montali offer some quality loose-leaf teas instead.
Both of the owners, Alberto and Malu, are charming and accomodating, and the entire staff was friendly and helpful during our stay. The other guests who were there were also very friendly, and we enjoyed meeting them.
Our room was very nice, with high ceilings and a rustic but modern feel. However, there was something in our room that aggravated my allergies. I'm not sure what, but I suspect the rooms may need more ventilation in the bathroom, as it took a while for the humidity to go away after we showered. Maybe a bathroom ventilation fan is in order?
The grounds of the hotel are absolutely gorgeous. There are great views over the olive grove. We didn't get a chance to explore the nearby countryside, but Lake Trasimeno looked very appealing when we drove by. Overall, staying at Montali is incredibly peaceful. You're in a beautiful remote spot, with friendly staff, and you're served incredible vegan meals. What more could you ask for?
After our first night there, we were already discussing when we'd go back again. Next time, we plan to stay for longer.
If you're planning a trip to Italy anywhere near Montali (or even not near), I can't recommend this place highly enough. I'm sure that it will be one of highlights of your trip.