Oh yeah @MattB summarized in YoYoStringLab - New Formula
AMMO - This is a thick version of Type X that I did for JD. Super nice for slack, but if you do a lot of layers in the gap, you have to be on top of your game. Softest of them all.
Venom - Eric Koloski wanted something for his slack style, and if possible in a regular thickness, so we came up with Venom. It slacks more like AMMO, but about the same thickness as Type X. It’s softish, but not as soft as Type X.
Plutonium - Evan Nagao tried out the existing types, and based on his thoughts, I did string variants and tensions to eventually come up with Plutonium. It’s slightly thicker than Type X and Venom without feeling big. The tension is tuned to Evan’s preference. It’s softer than basic string, but Type X is slightly softer than Plutonium. So it’s a nice balance of performance and feel.
Here’s a closeup pic I’ve been meaning to take from the $9.25 YYSL sampler pack which is a fantastic starting point:
||more slack-y, less soft
||fatter, less soft
So basically Type X and Venom are roughly regular kitty thickness (though a tiny bit fatter) whereas Venom is more like kitty fat and AMMO is definitely kitty XL.