I've never had a cutting hook on a multitool until I got a Charge TTI. It immediately showed itself to be remarkably useful. It makes a variety of cutting tasks so much easier, efficient and safe. Things like opening boxes and packages, cutting zip ties, controlled cuts through thicker, denser material, or in situations where a misstep with a knife can either damage the knife or damage what is being cut or both. It's proven itself to me to be an exceptionally useful and efficient tool. I would gladly trade the serrated blade on the XE6, which has recently become my multitool of choice, for a cutting hook.
The second cutting hook I got was in the form of the orange peeler on a Minichamp. This hook has a very sharp point on it, which while it mitigates some of the safety aspect of the Charge's tool, adds some cutting efficiency and capabilities. They should really rename this tool the clamshell pack opener. I love it and use it all the time

Now that I'm a cutting hook fanatic, I've been toying with the idea of sharpening the "multi-purpose" hook on my Super Tinker. Even though it's not in the ideal location, I think it would ultimately be more useful, just not sure there is enough metal there to make it work.
Anyway, I for one would love to see more cutting hooks popping up on multitools. Anyone else?