Chipping/damage is possible with both. That can be mitigated with a bottom grid or rubber mats. I chose SS for the chipping reaason and also have the grid. Im a dropper, so SS seemed safer. Three years later, no problems.

I dog sit in a number of homes and because I knew I would be remodeling in the near future, I kept an eye on products used in the various kitchens. Hands-down, the granite countertop with a coordinating cast iron sink was my favorite. It was just a pleasure to work around that sink, and it always looked good -- shiny and clean. The stainless/granite combo was just dreary. The silgranite sink was okay, but I couldn't get used to the texture of it, and didn't particularly care for the matte finish. I ultimately installed Kohler's Thunder Gray sink in my charcoal countertop and couldn't be more pleased.

If you go the cast iron route, be sure to get added support for it because they are heavy. Kohler makes a support kit that makes installation easy and the sink is well supported beyond the usual clips and adhesive.

I have a Kohler Whitehaven and I like it very much. It replaced an 18 year old cast iron sink which had no chips and still looked bright white after cleaning. I reused it in my basement kitchenette. I did see on the gardenweb that dark cast iron shows wear more than light.

I've been struggling with this same decision. Ordered sample chips of Silgranit & Elkay Quartz sinks and found the Elkay "Ricotta" color the whitest. I even tested it with overnight coffee grounds and ketchup and both cleaned off with dishsoap and a scrubby. I had a grey Silgranit with the low divide and and it was wonderful in terms of care and I found the low divide really useful. I used one side for clean hand-washed items but when I needed to get something bigger in there to hand-wash it was easy to do. But in this new house I want white due to the rest of the color palette. Unfortunately, even the whitest of white granite/quartz sink doesn't compare to the classic beauty of the enameled cast iron. So, I'm leaning towards the Kohler Whitehaven undermount w/ Smart Divide. It's great to hear what others have to say on the topic. :)

Twenty-year-old cast iron and its replacement:

SS sinks are really pretty when they're new. We have really hard water and even with a softener, I'd have to clean it with 50/50% Dawn/Vinegar 2-3 times a week. Won't do that again.

Black enameled cast iron shows wear much more than white - I think you told me that Joe:)