STOS has been gone a few years now, a disappointing loss.
As already mentioned the profiles on the heads are all the same, the difference is in the thickness. I always put small tanto tips on mine and I never had any trouble with any of them but the 160's were by far the most popular.
As for the ceramic coating, STOS came out with those a year or two before shutting down. Awesome heads, the ceramic coating is not for weight purposes it is super slick with the idea of enhancing penetration. They called them "Classic Ceramics" which I always thought was a little confusing, as they were the new heads. I currently have some I use for my lightest bow set up.