I went back and re-read the original post on this thread. As far as call surfaces, my slate calls generally have a medium-high pitch overall. The glass calls generally have a bit lower pitch, often with a fuller, or meatier sound (tone). I used bead blasted glass surfaces that require minimal conditioning and add a bit of "grit" to the sounds produced. I use powder blasted anodized aluminum for my aluminum calls. I promise you won't find a production aluminum call that will touch the sound of my aluminum calls. Many people don't like the sound of an aluminum call... simply because they haven't tried my aluminum calls. I sent an aluminum call made of canarywood to a very well known and respected box call maker at the request of a friend. The gentleman called and told me that it was one of only 2 aluminum calls that he had ever heard that he would use. He assured me that it would have a place in his vest. I have pictures on my website of 3 birds that fell to the canarywood/aluminum calls in spring 2006.
As for strikers, you can really change the sound of a call with the strikers that you use. I personally don't use any acrylic or carbon strikers... they just don't suit my taste. I have made strikers out of at least 30 different domestic and exotic woods. Striker wood and design can give extremely different sounds from the same call. A heavier striker will generally create a deeper tone in the call. A lighter striker will generally raise the pitch of the call. Due to the density of some woods, the thickness of the entire striker has to be adjusted to get the desired sound. The "right" striker wood comes down to what sound (pitch/tone) you want to create with your call.