I called turbonetics and turbo technology and they both said water cooled center sections are better but can be a pain in the butt to hook up.The turbo tech guy told me you can have a water cooled center section and run no water throgh it.
My new 63 has the water-cooled section. The holes are plugged up right now but I will get around to running the hoses and fittings sometime. I'd rather have the water-cooled section. Anything that can help reduce temps in that area is good.
from what I've read on it the big advantage is when you shut the car off. Supposedly it prevents the shaft heat from causing the oil to carbonize on it.