Yes the Springs and Congress Park are the preferred rooms. All rooms in those buildings are preferred, due to the location of the buildings. Not due to views like at other resorts. The Grandstand, Paddock and Carousel are standard category buildings, due to location. The room layouts are the same in all the buildings. A deluxe studio in the Springs is no different than one in the Grandstand.
Out of the Grandstand, Paddock and Carousel, I would and have chosen the Paddock. You save on points and just a short walk from Congress Park and the bridge to Disney Springs.
The Springs and Congress Park traditionally have been the most requested locations. So to get more villas booked at SSR, they upped the number of points required in those two locations and lowered the points required at the other three locations. So Paddock, Grandstand and Carousel are a little cheaper point wise.
We recently stayed in the Paddock area, saved some points vs. a preferred location, but were very close to the pool, bus stop, and an easy walk across the bridge to the main building for more pool fun and food!