I spent 5 nights in Hotel Schwan at the beginning of June. I had a suite in the renovated part of the hotel, overlooking the terrace. The room was spacious, clean and was serviced daily. No ironing facilties in the room, but when i requested it i got one in no time.
The food is great, service is friendly and efficient. Breakfast could be consumed on the lovely terrace as well in the mornings, with a fresh cup of Espresso :)! I can't say anything bad about this place really.
The location is fab, right on the bank of the Main river, car parking 50m and the entrance to the old town is next to the hotel. The castle is about 10 minutes walk.
There was some kind of a festival in front of the hotel, so better check on check in if you like peace and quiet just in case. I personally like these kind of events around the hotels i stay in.
Wertheim Village Outlet Shopping 10km, there's a shuttle bus from the town i think if you're into shopping :).