I have a white Irontones sink, undermounted. No scratches so far, I do have the Kohler grid in it. I had another Kohler cast iron sink in the kitchen before the reno, I love cast iron. I did consider a Silgranit, but couldn't find a white one to see in person, so I chickened out. The only picture I have handy is just after installation, before the strainer was even installed.

Monika and HU - I wonder if you're having problems because the Kohler plant had a fire several months ago and are really backed up in production, and thus, things are being rushed or done half ass to try to keep up with orders. I just replaced a double sink Kohler (can't remember the model but it was 20 years old) and wanted to go with a single basin. When I looked into Kohler, I was told (by Kohler) that they were back ordered nearly 6 months. (You could get it in almost any color but white, and white is what I wanted). I didn't have that time to wait so I went with a stainless steel (also by Kohler).

I've got the Kohler cast iron (and love it.) I'm sure if you dropped a glass in either the Kohler or the fireclay, the glass would likely break. I doubt there is an appreciable difference between the two. I haven't tried dropping a cast iron pan in my sink, but I did beat a Kohler display sink with a SS frying pan-no chips or scratches-though a non-enameled cast iron surface could possible scratch (just guessing here.)

I don't think the Highbridge is offered anymore without the enameled apron although they still may be in stock with a number of suppliers. The apron covers only the middle part of the front, so you have to custom build something to cover the front at each end (storage or tile) or cover the whole front with a tiled apron. Its essentially styled like a drop in tub but built as an alcove tub with flanges. This tub will offer the deepest bathing. The Mendota differs from the Bellwether also in that the Bellwether has a flattish rim around the top that you can set down things at least temporarily, but the Mendota has a thin and beveled rim, which probably makes the interior a bit wider, but I don't think you could put a shampoo bottle down or sit on the edge of this tub comfortably. The other option is the Kohler Dynametric. I just bought the Bellwether 30x60 without the angled front but it is not installed yet.