I also recently stayed at the Sofitel. The Novatel is next door and even less expensive, but I don't know about the room size. The Sofitel was a pleasant surprise, not up to the Westin's standards but a nice and sizable room at a very good price.
There's a large park near the hotel, which is great for jogging. During the evening there's nothing around, but there's a metro stop around the corner from the hotel that will get you downtown in a few minutes.
It's near the freeway, so a reasonable location if you need to drive somewhere outside of the city center.
With the hotel situation in Madrid, I've found this to be a reasonable alternative in some cases.