A lot of people are disagreeing with what I said, and that's fine, because I said it. I don't think flippers are practical knives.
I have large hands. I typically wear XL gloves or larger. Positioning my hand to push on a flipper tab is not practical to me. I've tried different shapes and sizes, with and without gloves, and they are impractical. I carry my knives tip up, so when I reach into my pocket, my hand is where it needs to be to deploy the blade. It's not about speed, it's about less steps to deploy the blade. With flippers, I have to pull the knife out, reposition my hand and index finger on the flipper, then deploy the blade. Not all flippers flip the same, and not all flippers have thumb studs/holes/discs. So if the blade doesn't deploy 100%, there is nowhere for me to push with my thumb. I've had this happen many times in the past. There are thousands of threads on here, asking how to flip a flipper, because some people just can't do it. There are techniques to opening a flipper... Don't deny it. That's not practical.