I had no idea......

[Pilot1]

I liked my first 0551 so much I bought a second. Did the same thing with the 0560. I carry them about equally now. Different style knives but both are ver useful.

 

[stratlanta]

I think a lot of it is technique as I can open my 0560 using the thumbstuds perfectly and just as fast as using the flipper.

Sooooo, swallowing my pride a bit here and saying that this was 100% accurate. After this post I did a bit of interweb searching and found a bunch of 550 videos on yootube. Turns out that the people having trouble opening theirs were trying to do it the same way I was. Those who were flipping theirs open without issue were using an entirely different technique. Watched a few of these, paid attention, went to where I keep my knives, pulled out the 0550 and 0551 and... bam... opened like a champ! Learn something new on this forum every day!