Having stayed at both, I recommend CSR, hands down. CBR, while very pretty, just doesn't compare, IMHO.
I think CSR has the most beautiful landscaping, the Dig Site pool area is wonderful, and the entire resort just oozes ambience. A walk along the lake at night is not to be missed, the bus service is great, and the food court is a cut above.
The main entrance (El Centro) contains check-in, bell services, food court, restaurant, lounge and gift shop. We were in Casitas 2, which was just a few minutes walk to El Centro, very close to a bus stop, but quite a hike to the Dig Site. There was a quiet pool there though.