The Hotel Fex is in a remote alpine valley which you must either walk to or take a horse drawn "taxi". Departure point is Sils Maria. We chose to take the taxi and they dropped us at the Hotel Fex for lunch, returning to collect us 90 mins later. Cost of the taxi was 160frs plus a small tip to the driver and we split this amongst 4 people. A large shared taxi costs about the same.
The Val Fex is beautiful. From the hotel you have a view of glaciers and mountain peaks. There is a terrace where they serve lunch but since it was coolish we ate inside. Food was simple but very good and the service was impeccable - the waitress had a lovely smile as well. There is not much choice as far as places to eat in the Val Fex - Hotel Fex and the Hotel Sonne which is slightly closer to Sils Maria. I think the Hotel Fex was worth the additional time spent for the ambiance and the views but since I have not eaten at the Sonne I cannot compare the food etc.