I don't really like them. I just got my first knife with thumb stud on it a few months ago and I'd sit in front of the TV for a few days with the knife trying to master that thumb flick so that it felt smooth and natural. May seem cheesy but I might have felt a little proud of mastering this little move. When someone shows me an assisted or automatic knife in a knife shop and all I gotta do is press a button and the knife flips out... it just seems really unsatisfying.