I got some of the 76 Sliders. I'll probably make some flat/angle mounts for them as well. I also have some pyrolamas as well.
Looking at the 76 Sliders before they came in, I thought they were be a little beefier or possibly made from some other material (like HDPE) rather than plastic. They are also a bit hollow on the sides. I guess it doesn't matter as long as they work and hold up over time.
Chris