This is a very subjective question. Will you be spending a lot of time at the resort? Will you use the pool? Will you have drinks? Will you dine at the resort?
We spent 10 days at CSR in October this past year. Loved it. But I'd be hesitant to recommend it for October of next year because the new tower and lagoon restaurant should be open by then, and it remains to be seen how that will impact the existing restaurants, pools, buses. etc. But similarly, at CBR, the Skyliner should be open by then too so who knows what impact that will have on the resort. I do think it would be less of an impact that the new tower at CSR, though.
CBR has been recently renovated with a new food court, restaurant, etc. I believe the rooms at CSR are more recently renovated. CBR is a larger resort. CSR caters to the convention attendees so there tends to be more groups and business travelers, which has pros and cons. They are both pretty centrally located.
IMO, it depends on what your priorities are. I could make arguments for either resort. We love CSR, but have not stayed at CBR since the recent renovations. We're considering trying it next it again next trip.