Florence in great, because it has the tourist attractions without feeling too touristy. The hotels that you mentioned are both great and are located right next to each other. I have stayed at the Westin in a river-view corner room and it is one of the best hotel rooms I have ever stayed in. I have certainly stayed in larger, more luxurious suites, but for a normal room this one near the top of the list. It had a small balcony that looked out over the small piazza towards the Grand Hotel and out onto the Arno River. There is another window on the adjacent wall that has a different view over the river with views of the Tuscan hillside and the Ponte Vecchio to the left. The room was great and the views spectacular.

This hotel provides a great base for exploring the city. Florence is a walking city and everything is close by. We found a great restaurant off-the beaten-path and we went back three times during our trip. It's only a 5 minute walk from the hotel and the food was great and cheap. A meal with wine was only about 10 Euro per person. It was not a tourist spot, but instead filled with locals. The owner would come around and offer you menu choices as they didn't have printed menus and the offerings changed nightly. Eating at a place like this gave the trip a more relaxed and authentic feel because we knew we couldn't find that back home. There was a laundry mat next door (that's how we found the restaurant) if you need to wash any clothes on your trip.

Florence is full of great sights. Be sure to climb to the top of the Duomo is you have time and aren't claustrophobic. The Uffizi gallery is great and there are several worthwhile churches close by. My favorite thing was the Medici Chapel which I believe was behind San Lorenzo church. It is small, but amazing.

I hope some of this helps. Please PM me if you have any specific questions. I will also look at the rest of your itinerary later and see what else I can offer.