I’ll let others comment about how they like it, but I can answer your questions about materials and comparisons between the two. Venom and Ammo are both made of polyester, but different types.
Ammo is thicker and slightly softer. It was originally developed for JD, since he liked my string, but he wanted a thicker string that’s good for his slack style of play. Its thickness is also good for creative and horizontal binds. If you like to get lots of layers into the gap, its thickness might be more challenging.
Venom was formulated for Eric Koloski. He also has a slack style of play but was really happy with a new string under development that had the slack ability of Ammo, but in a regular thickness. It became his signature string.
Both have a good balance of controlled slack speed. Not too lightning fast, not to weak or slow.